AltOS

- AltOS is a operating system built for the 8051-compatible - processor found in the TI cc1111 microcontroller. It's designed - to be small and easy to program with. The main features are: -

Multi-tasking. While the 8051 doesn't provide separate - address spaces, it's often easier to write code that operates - in separate threads instead of tying everything into one giant - event loop. +

Revision History
Revision 1.1	05 November 2012
Portable version
Revision 0.1	22 November 2010
Initial content

Table of Contents

1. Overview

2. AltOS Porting Layer

1. Low-level CPU operations

1.1. ao_arch_block_interrupts/ao_arch_release_interrupts
1.2. ao_arch_save_regs, ao_arch_save_stack, + ao_arch_restore_stack
1.3. ao_arch_wait_interupt

2. GPIO operations

2.1. GPIO setup
2.2. Reading and writing GPIO pins

3. Programming the 8051 with SDCC

1. 8051 memory spaces

1.1. __data
1.2. __idata
1.3. __xdata
1.4. __pdata
1.5. __code
1.6. __bit
1.7. __sfr, __sfr16, __sfr32, __sbit

2. Function calls on the 8051

2.1. __reentrant functions
2.2. Non __reentrant functions
2.3. __interrupt functions
2.4. __critical functions and statements

4. Task functions

1. ao_add_task
2. ao_exit
3. ao_sleep
4. ao_wakeup
5. ao_alarm
6. ao_start_scheduler
7. ao_clock_init

5. Timer Functions

1. ao_time
2. ao_delay
3. ao_timer_set_adc_interval
4. ao_timer_init

6. AltOS Mutexes

1. ao_mutex_get
2. ao_mutex_put

7. DMA engine

1. CC1111 DMA Engine

1.1. ao_dma_alloc
1.2. ao_dma_set_transfer
1.3. ao_dma_start
1.4. ao_dma_trigger
1.5. ao_dma_abort

2. STM32L DMA Engine

2.1. ao_dma_alloc
2.2. ao_dma_set_transfer
2.3. ao_dma_set_isr
2.4. ao_dma_start
2.5. ao_dma_done_transfer
2.6. ao_dma_abort

8. Stdio interface

1. putchar
2. getchar
3. flush
4. ao_add_stdio

9. Command line interface

1. ao_cmd_register
2. ao_cmd_lex
3. ao_cmd_put16
4. ao_cmd_put8
5. ao_cmd_white
6. ao_cmd_hex
7. ao_cmd_decimal
8. ao_match_word
9. ao_cmd_init

10. USB target device

1. ao_usb_flush
2. ao_usb_putchar
3. ao_usb_pollchar
4. ao_usb_getchar
5. ao_usb_disable
6. ao_usb_enable
7. ao_usb_init

11. Serial peripherals

1. ao_serial_getchar
2. ao_serial_putchar
3. ao_serial_drain
4. ao_serial_set_speed
5. ao_serial_init

12. CC1111 Radio peripheral

1. Radio Introduction

2. ao_radio_set_telemetry

3. ao_radio_set_packet

4. ao_radio_set_rdf

5. ao_radio_idle

6. ao_radio_get

7. ao_radio_put

8. ao_radio_abort

9. Radio Telemetry

9.1. ao_radio_send
9.2. ao_radio_recv

10. Radio Direction Finding

10.1. ao_radio_rdf

11. Radio Packet Mode

11.1. ao_packet_putchar
11.2. ao_packet_pollchar
11.3. ao_packet_slave_start
11.4. ao_packet_slave_stop
11.5. ao_packet_slave_init
11.6. ao_packet_master_init

Chapter 1. Overview

+ AltOS is a operating system built for a variety of + microcontrollers used in Altus Metrum devices. It has a simple + porting layer for each CPU while providing a convenient + operating enviroment for the developer. AltOS currently + supports three different CPUs: +

+ STM32L series from ST Microelectronics. This ARM Cortex-M3 + based microcontroller offers low power consumption and a + wide variety of built-in peripherals. Altus Metrum uses + this in the TeleMega, MegaDongle and TeleLCO projects. +
+ CC1111 from Texas Instruments. This device includes a + fabulous 10mW digital RF transceiver along with an + 8051-compatible processor core and a range of + peripherals. This is used in the TeleMetrum, TeleMini, + TeleDongle and TeleFire projects which share the need for + a small microcontroller and an RF interface. +
+ ATmega32U4 from Atmel. This 8-bit AVR microcontroller is + one of the many used to create Arduino boards. The 32U4 + includes a USB interface, making it easy to connect to + other computers. Altus Metrum used this in prototypes of + the TeleScience and TelePyro boards; those have been + switched to the STM32L which is more capable and cheaper. +

+ Among the features of AltOS are: +

Multi-tasking. While microcontrollers often don't + provide separate address spaces, it's often easier to write + code that operates in separate threads instead of tying + everything into one giant event loop.
Non-preemptive. This increases latency for thread switching but reduces the number of places where context switching can occur. It also simplifies the operating system @@ -61,7 +85,109 @@
As you can see, a long sequence of subsystems are initialized and then the scheduler is started. -

Chapter 2. Programming the 8051 with SDCC

Table of Contents

1. 8051 memory spaces

1.1. __data
1.2. __idata
1.3. __xdata
1.4. __pdata
1.5. __code
1.6. __bit
1.7. __sfr, __sfr16, __sfr32, __sbit

2. Function calls on the 8051

2.1. __reentrant functions
2.2. Non __reentrant functions
2.3. __interrupt functions
2.4. __critical functions and statements

Chapter 2. AltOS Porting Layer

Table of Contents

1. Low-level CPU operations

1.1. ao_arch_block_interrupts/ao_arch_release_interrupts
1.2. ao_arch_save_regs, ao_arch_save_stack, + ao_arch_restore_stack
1.3. ao_arch_wait_interupt

2. GPIO operations

2.1. GPIO setup
2.2. Reading and writing GPIO pins

+ AltOS provides a CPU-independent interface to various common + microcontroller subsystems, including GPIO pins, interrupts, + SPI, I2C, USB and asynchronous serial interfaces. By making + these CPU-independent, device drivers, generic OS and + application code can all be written that work on any supported + CPU. Many of the architecture abstraction interfaces are + prefixed with ao_arch. +

1. Low-level CPU operations

+ These primitive operations provide the abstraction needed to + run the multi-tasking framework while providing reliable + interrupt delivery. +

1.1. ao_arch_block_interrupts/ao_arch_release_interrupts

+	  static inline void
+	  ao_arch_block_interrupts(void);
+	  
+	  static inline void
+	  ao_arch_release_interrupts(void);
+

+ These disable/enable interrupt delivery, they may not + discard any interrupts. Use these for sections of code that + must be atomic with respect to any code run from an + interrupt handler. +

1.2. ao_arch_save_regs, ao_arch_save_stack, + ao_arch_restore_stack

+	  static inline void
+	  ao_arch_save_regs(void);
+
+	  static inline void
+	  ao_arch_save_stack(void);
+
+	  static inline void
+	  ao_arch_restore_stack(void);
+

+ These provide all of the support needed to switch between + tasks.. ao_arch_save_regs must save all CPU registers to the + current stack, including the interrupt enable + state. ao_arch_save_stack records the current stack location + in the current ao_task structure. ao_arch_restore_stack + switches back to the saved stack, restores all registers and + branches to the saved return address. +

1.3. ao_arch_wait_interupt

+	  #define ao_arch_wait_interrupt()
+

+ This stops the CPU, leaving clocks and interrupts + enabled. When an interrupt is received, this must wake up + and handle the interrupt. ao_arch_wait_interrupt is entered + with interrupts disabled to ensure that there is no gap + between determining that no task wants to run and idling the + CPU. It must sleep the CPU, process interrupts and then + disable interrupts again. If the CPU doesn't have any + reduced power mode, this must at the least allow pending + interrupts to be processed. +

2. GPIO operations

+ These functions provide an abstract interface to configure and + manipulate GPIO pins. +

2.1. GPIO setup

+ These macros may be invoked at system initialization time to + configure pins as needed for system operation. One tricky + aspect is that some chips provide direct access to specific + GPIO pins while others only provide access to a whole + register full of pins. To support this, the GPIO macros + provide both port+bit and pin arguments. Simply define the + arguments needed for the target platform and leave the + others undefined. +

2.1.1. ao_enable_output

+	    #define ao_enable_output(port, bit, pin, value)
+

+ Set the specified port+bit (also called 'pin') for output, + initializing to the specified value. The macro must avoid + driving the pin with the opposite value if at all + possible. +

2.1.2. ao_enable_input

+	    #define ao_enable_input(port, bit, mode)
+

+ Sets the specified port/bit to be an input pin. 'mode' is + a combination of one or more of the following. Note that + some platforms may not support the desired mode. In that + case, the value will not be defined so that the program + will fail to compile. +

+ AO_EXTI_MODE_PULL_UP. Apply a pull-up to the pin; a + disconnected pin will read as 1. +
+ AO_EXTI_MODE_PULL_DOWN. Apply a pull-down to the pin; + a disconnected pin will read as 0. +
+ 0. Don't apply either a pull-up or pull-down. A + disconnected pin will read an undetermined value. +

2.2. Reading and writing GPIO pins

+ These macros read and write individual GPIO pins. +

2.2.1. ao_gpio_set

+	    #define ao_gpio_set(port, bit, pin, value)
+

+ Sets the specified port/bit or pin to the indicated value +

2.2.2. ao_gpio_get

+	    #define ao_gpio_get(port, bit, pin)
+

+ Returns either 1 or 0 depending on whether the input to + the pin is high or low. +

Chapter 3. Programming the 8051 with SDCC

Table of Contents

1. 8051 memory spaces

1.1. __data
1.2. __idata
1.3. __xdata
1.4. __pdata
1.5. __code
1.6. __bit
1.7. __sfr, __sfr16, __sfr32, __sbit

2. Function calls on the 8051

2.1. __reentrant functions
2.2. Non __reentrant functions
2.3. __interrupt functions
2.4. __critical functions and statements

The 8051 is a primitive 8-bit processor, designed in the mists of time in as few transistors as possible. The architecture is highly irregular and includes several separate memory @@ -69,7 +195,10 @@ stack itself is of limited size. While SDCC papers over the instruction set, it is not completely able to hide the memory architecture from the application designer. -

1. 8051 memory spaces

+ When built on other architectures, the various SDCC-specific + symbols are #defined as empty strings so they don't affect the compiler. +

1. 8051 memory spaces

The __data/__xdata/__code memory spaces below were completely separate in the original 8051 design. In the cc1111, this isn't true—they all live in a single unified 64kB address @@ -83,7 +212,7 @@ is decorated with a memory space identifier which clutters the code but makes the resulting code far smaller and more efficient. -

1.1. __data

The 8051 can directly address these 128 bytes of memory. This makes them precious so they should be reserved for frequently addressed values. Oh, just to @@ -93,42 +222,42 @@ these registers located at 0x00 - 0x1F. AltOS uses only the first bank at 0x00 - 0x07, leaving the other 24 bytes available for other data. -

1.2. __idata

There are an additional 128 bytes of internal memory that share the same address space as __data but which cannot be directly addressed. The stack normally occupies this space and so AltOS doesn't place any static storage here. -

1.3. __xdata

This is additional general memory accessed through a single 16-bit address register. The CC1111F32 has 32kB of memory available here. Most program data should live in this memory space. -

1.4. __pdata

This is an alias for the first 256 bytes of __xdata memory, but uses a shorter addressing mode with single global 8-bit value for the high 8 bits of the address and any of several 8-bit registers for the low 8 bits. AltOS uses a few bits of this memory, it should probably use more. -

1.5. __code

All executable code must live in this address space, but you can stick read-only data here too. It is addressed using the 16-bit address register and special 'code' access opcodes. Anything read-only should live in this space. -

1.6. __bit

The 8051 has 128 bits of bit-addressible memory that lives in the __data segment from 0x20 through 0x2f. Special instructions access these bits in a single atomic operation. This isn't so much a separate address space as a special addressing mode for a few bytes in the __data segment. -

1.7. sfr, sfr16, sfr32, sbit

Access to physical registers in the device use this mode which declares the variable name, it's type and the address it lives at. No memory is allocated for these variables. -

2. Function calls on the 8051

Because stack addressing is expensive, and stack space limited, the default function call declaration in SDCC allocates all parameters and local variables in static global @@ -136,7 +265,7 @@ non-reentrant, and also consume space for parameters and locals even when they are not running. The benefit is smaller code and faster execution. -

2.1. __reentrant functions

All functions which are re-entrant, either due to recursion or due to a potential context switch while executing, should be marked as __reentrant so that their parameters and local @@ -149,7 +278,7 @@ invoked can also be marked as __reentrant. The resulting code will be larger, but the savings in memory are frequently worthwhile. -

2.2. Non __reentrant functions

All parameters and locals in non-reentrant functions can have data space decoration so that they are allocated in __xdata, __pdata or __data space as desired. This can avoid @@ -161,14 +290,14 @@ non-reentrant. Because of this, interrupt handlers must not invoke any library functions, including the multiply and divide code. -

2.3. __interrupt functions

Interrupt functions are declared with with an __interrupt decoration that includes the interrupt number. SDCC saves and restores all of the registers in these functions and uses the 'reti' instruction at the end so that they operate as stand-alone interrupt handlers. Interrupt functions may call the ao_wakeup function to wake AltOS tasks. -

2.4. __critical functions and statements

SDCC has built-in support for suspending interrupts during critical code. Functions marked as __critical will have interrupts suspended for the whole period of @@ -176,10 +305,12 @@ __critical which blocks interrupts during the execution of that statement. Keeping critical sections as short as possible is key to ensuring that interrupts are handled as - quickly as possible. -

Chapter 3. Task functions

Table of Contents

1. ao_add_task
2. ao_exit
3. ao_sleep
4. ao_wakeup
5. ao_alarm
6. ao_start_scheduler
7. ao_clock_init

+ quickly as possible. AltOS doesn't use this form in shared + code as other compilers wouldn't know what to do. Use + ao_arch_block_interrupts and ao_arch_release_interrupts instead. +

Chapter 4. Task functions

Table of Contents

1. ao_add_task
2. ao_exit
3. ao_sleep
4. ao_wakeup
5. ao_alarm
6. ao_start_scheduler
7. ao_clock_init

This chapter documents how to create, destroy and schedule AltOS tasks. -

1. ao_add_task

+    
1. ao_add_task
 	void
 	ao_add_task(__xdata struct ao_task * task,
 	            void (*start)(void),
@@ -190,12 +321,12 @@
 	display), and the start address. It does not switch to the
 	new task. 'start' must not ever return; there is no place
 	to return to.
-      
2. ao_exit
+      
2. ao_exit
 	void
 	ao_exit(void)
       

 	This terminates the current task.
-      
3. ao_sleep
+      
3. ao_sleep
 	void
 	ao_sleep(__xdata void *wchan)
       

@@ -205,17 +336,19 @@
 	it returns 1. This is the only way to switch to another task.
       

 	Because ao_wakeup wakes every task waiting on a particular
-	location, ao_sleep should be used in a loop that first
-	checks the desired condition, blocks in ao_sleep and then
-	rechecks until the condition is satisfied. If the
-	location may be signaled from an interrupt handler, the
-	code will need to block interrupts by using the __critical
-	label around the block of code. Here's a complete example:
+	location, ao_sleep should be used in a loop that first checks
+	the desired condition, blocks in ao_sleep and then rechecks
+	until the condition is satisfied. If the location may be
+	signaled from an interrupt handler, the code will need to
+	block interrupts around the block of code. Here's a complete
+	example:
 	
-	  __critical while (!ao_radio_done)
+	  ao_arch_block_interrupts();
+	  while (!ao_radio_done)
 	          ao_sleep(&ao_radio_done);
+	  ao_arch_release_interrupts();
 	

-      
4. ao_wakeup
+      
4. ao_wakeup
 	void
 	ao_wakeup(__xdata void *wchan)
       

@@ -229,100 +362,109 @@
 	          RFIF &= ~RFIF_IM_DONE;
 	  }

- Note that this need not be enclosed in __critical as the - ao_sleep block can only be run from normal mode, and so - this sequence can never be interrupted with execution of - the other sequence. -

5. ao_alarm

+ Note that this need not block interrupts as the ao_sleep block + can only be run from normal mode, and so this sequence can + never be interrupted with execution of the other sequence. +

5. ao_alarm

 	void
-	ao_alarm(uint16_t delay)
+	ao_alarm(uint16_t delay);
+
+	void
+	ao_clear_alarm(void);

- Schedules an alarm to fire in at least 'delay' ticks. If - the task is asleep when the alarm fires, it will wakeup - and ao_sleep will return 1. + Schedules an alarm to fire in at least 'delay' ticks. If the + task is asleep when the alarm fires, it will wakeup and + ao_sleep will return 1. ao_clear_alarm resets any pending + alarm so that it doesn't fire at some arbitrary point in the + future.

 	  ao_alarm(ao_packet_master_delay);
-	  __critical while (!ao_radio_dma_done)
+	  ao_arch_block_interrupts();
+	  while (!ao_radio_dma_done)
 	          if (ao_sleep(&ao_radio_dma_done) != 0)
 	                  ao_radio_abort();
+	  ao_arch_release_interrupts();
+	  ao_clear_alarm();

In this example, a timeout is set before waiting for incoming radio data. If no data is received before the timeout fires, ao_sleep will return 1 and then this code will abort the radio receive operation. -

6. ao_start_scheduler

 	void
-	ao_start_scheduler(void)
+	ao_start_scheduler(void);

This is called from 'main' when the system is all initialized and ready to run. It will not return. -

7. ao_clock_init

 	void
-	ao_clock_init(void)
+	ao_clock_init(void);

- This turns on the external 48MHz clock then switches the - hardware to using it. This is required by many of the - internal devices like USB. It should be called by the - 'main' function first, before initializing any of the - other devices in the system. -

Chapter 4. Timer Functions

Table of Contents

1. ao_time
2. ao_delay
3. ao_timer_set_adc_interval
4. ao_timer_init

- AltOS sets up one of the cc1111 timers to run at 100Hz and + This initializes the main CPU clock and switches to it. +

Chapter 5. Timer Functions

Table of Contents

1. ao_time
2. ao_delay
3. ao_timer_set_adc_interval
4. ao_timer_init

+ AltOS sets up one of the CPU timers to run at 100Hz and exposes this tick as the fundemental unit of time. At each interrupt, AltOS increments the counter, and schedules any tasks - waiting for that time to pass, then fires off the ADC system to + waiting for that time to pass, then fires off the sensors to collect current data readings. Doing this from the ISR ensures - that the ADC values are sampled at a regular rate, independent + that the values are sampled at a regular rate, independent of any scheduling jitter. -

1. ao_time

 	uint16_t
 	ao_time(void)

Returns the current system tick count. Note that this is only a 16 bit value, and so it wraps every 655.36 seconds. -

2. ao_delay

 	void
 	ao_delay(uint16_t ticks);

Suspend the current task for at least 'ticks' clock units. -

3. ao_timer_set_adc_interval

 	void
 	ao_timer_set_adc_interval(uint8_t interval);

This sets the number of ticks between ADC samples. If set to 0, no ADC samples are generated. AltOS uses this to slow down the ADC sampling rate to save power. -

4. ao_timer_init

 	void
 	ao_timer_init(void)

- This turns on the 100Hz tick using the CC1111 timer 1. It - is required for any of the time-based functions to - work. It should be called by 'main' before ao_start_scheduler. -

Chapter 5. AltOS Mutexes

Table of Contents

1. ao_mutex_get
2. ao_mutex_put

+ This turns on the 100Hz tick. It is required for any of the + time-based functions to work. It should be called by 'main' + before ao_start_scheduler. +

Chapter 6. AltOS Mutexes

Table of Contents

1. ao_mutex_get
2. ao_mutex_put

AltOS provides mutexes as a basic synchronization primitive. Each mutexes is simply a byte of memory which holds 0 when the mutex is free or the task id of the owning task when the mutex is owned. Mutex calls are checked—attempting to acquire a mutex already held by the current task or releasing a mutex not held by the current task will both cause a panic. -

1. ao_mutex_get

 	void
 	ao_mutex_get(__xdata uint8_t *mutex);

Acquires the specified mutex, blocking if the mutex is owned by another task. -

2. ao_mutex_put

 	void
 	ao_mutex_put(__xdata uint8_t *mutex);

Releases the specified mutex, waking up all tasks waiting for it. -

Chapter 6. CC1111 DMA engine

Table of Contents

1. ao_dma_alloc
2. ao_dma_set_transfer
3. ao_dma_start
4. ao_dma_trigger
5. ao_dma_abort

- The CC1111 contains a useful bit of extra hardware in the form - of five programmable DMA engines. They can be configured to copy - data in memory, or between memory and devices (or even between - two devices). AltOS exposes a general interface to this hardware - and uses it to handle radio and SPI data. +

Chapter 7. DMA engine

Table of Contents

1. CC1111 DMA Engine

1.1. ao_dma_alloc
1.2. ao_dma_set_transfer
1.3. ao_dma_start
1.4. ao_dma_trigger
1.5. ao_dma_abort

2. STM32L DMA Engine

2.1. ao_dma_alloc
2.2. ao_dma_set_transfer
2.3. ao_dma_set_isr
2.4. ao_dma_start
2.5. ao_dma_done_transfer
2.6. ao_dma_abort

+ The CC1111 and STM32L both contain a useful bit of extra + hardware in the form of a number of programmable DMA + engines. They can be configured to copy data in memory, or + between memory and devices (or even between two devices). AltOS + exposes a general interface to this hardware and uses it to + handle both internal and external devices. +

+ Because the CC1111 and STM32L DMA engines are different, the + interface to them is also different. As the DMA engines are + currently used to implement platform-specific drivers, this + isn't yet a problem.

Code using a DMA engine should allocate one at startup time. There is no provision to free them, and if you run out, @@ -334,63 +476,114 @@ from hardware to memory, that trigger event is supplied by the hardware device. When copying data from memory to hardware, the transfer is usually initiated by software. -

1. ao_dma_alloc

-	uint8_t
-	ao_dma_alloc(__xdata uint8_t *done)
-

- Allocates a DMA engine, returning the identifier. Whenever - this DMA engine completes a transfer. 'done' is cleared - when the DMA is started, and then receives the - AO_DMA_DONE bit on a successful transfer or the - AO_DMA_ABORTED bit if ao_dma_abort was called. Note that - it is possible to get both bits if the transfer was - aborted after it had finished. -

2. ao_dma_set_transfer

-	void
-	ao_dma_set_transfer(uint8_t id,
-	                    void __xdata *srcaddr,
-	                    void __xdata *dstaddr,
-	                    uint16_t count,
-	                    uint8_t cfg0,
-	                    uint8_t cfg1)
-

- Initializes the specified dma engine to copy data - from 'srcaddr' to 'dstaddr' for 'count' units. cfg0 and - cfg1 are values directly out of the CC1111 documentation - and tell the DMA engine what the transfer unit size, - direction and step are. -

3. ao_dma_start

-	void
-	ao_dma_start(uint8_t id);
-

- Arm the specified DMA engine and await a signal from - either hardware or software to start transferring data. -

4. ao_dma_trigger

-	void
-	ao_dma_trigger(uint8_t id)
-

- Trigger the specified DMA engine to start copying data. -

5. ao_dma_abort

-	void
-	ao_dma_abort(uint8_t id)
-

- Terminate any in-progress DMA transation, marking its - 'done' variable with the AO_DMA_ABORTED bit. -

Chapter 7. SDCC Stdio interface

Table of Contents

1. putchar
2. getchar
3. flush
4. ao_add_stdio

- AltOS offers a stdio interface over both USB and the RF packet - link. This provides for control of the device localy or - remotely. This is hooked up to the stdio functions in SDCC by - providing the standard putchar/getchar/flush functions. These - automatically multiplex the two available communication - channels; output is always delivered to the channel which - provided the most recent input. -

1. putchar

+    
1. CC1111 DMA Engine
1.1. ao_dma_alloc
+	  uint8_t
+	  ao_dma_alloc(__xdata uint8_t *done)
+	

+	  Allocate a DMA engine, returning the identifier.  'done' is
+	  cleared when the DMA is started, and then receives the
+	  AO_DMA_DONE bit on a successful transfer or the
+	  AO_DMA_ABORTED bit if ao_dma_abort was called. Note that it
+	  is possible to get both bits if the transfer was aborted
+	  after it had finished.
+	
1.2. ao_dma_set_transfer
+	  void
+	  ao_dma_set_transfer(uint8_t id,
+	  void __xdata *srcaddr,
+	  void __xdata *dstaddr,
+	  uint16_t count,
+	  uint8_t cfg0,
+	  uint8_t cfg1)
+	

+	  Initializes the specified dma engine to copy data
+	  from 'srcaddr' to 'dstaddr' for 'count' units. cfg0 and
+	  cfg1 are values directly out of the CC1111 documentation
+	  and tell the DMA engine what the transfer unit size,
+	  direction and step are.
+	
1.3. ao_dma_start
+	  void
+	  ao_dma_start(uint8_t id);
+	

+	  Arm the specified DMA engine and await a signal from
+	  either hardware or software to start transferring data.
+	
1.4. ao_dma_trigger
+	  void
+	  ao_dma_trigger(uint8_t id)
+	

+	  Trigger the specified DMA engine to start copying data.
+	
1.5. ao_dma_abort
+	  void
+	  ao_dma_abort(uint8_t id)
+	

+	  Terminate any in-progress DMA transation, marking its
+	  'done' variable with the AO_DMA_ABORTED bit.
+	
2. STM32L DMA Engine
2.1. ao_dma_alloc
+	  uint8_t ao_dma_done[];
+
+	  void
+	  ao_dma_alloc(uint8_t index);
+	

+	  Reserve a DMA engine for exclusive use by one
+	  driver.
+	
2.2. ao_dma_set_transfer
+	  void
+	  ao_dma_set_transfer(uint8_t id,
+	  void *peripheral,
+	  void *memory,
+	  uint16_t count,
+	  uint32_t ccr);
+	

+	  Initializes the specified dma engine to copy data between
+	  'peripheral' and 'memory' for 'count' units. 'ccr' is a
+	  value directly out of the STM32L documentation and tells the
+	  DMA engine what the transfer unit size, direction and step
+	  are.
+	
2.3. ao_dma_set_isr
+	  void
+	  ao_dma_set_isr(uint8_t index, void (*isr)(int))
+	

+	  This sets a function to be called when the DMA transfer
+	  completes in lieu of setting the ao_dma_done bits. Use this
+	  when some work needs to be done when the DMA finishes that
+	  cannot wait until user space resumes.
+	
2.4. ao_dma_start
+	  void
+	  ao_dma_start(uint8_t id);
+	

+	  Arm the specified DMA engine and await a signal from either
+	  hardware or software to start transferring data.
+	  'ao_dma_done[index]' is cleared when the DMA is started, and
+	  then receives the AO_DMA_DONE bit on a successful transfer
+	  or the AO_DMA_ABORTED bit if ao_dma_abort was called. Note
+	  that it is possible to get both bits if the transfer was
+	  aborted after it had finished.
+	
2.5. ao_dma_done_transfer
+	  void
+	  ao_dma_done_transfer(uint8_t id);
+	

+	  Signals that a specific DMA engine is done being used. This
+	  allows multiple drivers to use the same DMA engine safely.
+	
2.6. ao_dma_abort
+	  void
+	  ao_dma_abort(uint8_t id)
+	

+	  Terminate any in-progress DMA transation, marking its
+	  'done' variable with the AO_DMA_ABORTED bit.
+

Chapter 8. Stdio interface

Table of Contents

1. putchar
2. getchar
3. flush
4. ao_add_stdio

+ AltOS offers a stdio interface over USB, serial and the RF + packet link. This provides for control of the device localy or + remotely. This is hooked up to the stdio functions by providing + the standard putchar/getchar/flush functions. These + automatically multiplex the available communication channels; + output is always delivered to the channel which provided the + most recent input. +

1. putchar

 	void
 	putchar(char c)

Delivers a single character to the current console device. -

2. getchar

 	char
 	getchar(void)

@@ -398,13 +591,13 @@ console devices. The current console device is set to that which delivered this character. This blocks until a character is available. -

3. flush

 	void
 	flush(void)

Flushes the current console device output buffer. Any pending characters will be delivered to the target device. - xo

4. ao_add_stdio

+ xo

4. ao_add_stdio

 	void
 	ao_add_stdio(char (*pollchar)(void),
 	                   void (*putchar)(char),
@@ -426,13 +619,13 @@
 	'flush' forces the output buffer to be flushed. It may
 	block until the buffer is delivered, but it is not
 	required to do so.
-

Chapter 8. Command line interface

Table of Contents

1. ao_cmd_register
2. ao_cmd_lex
3. ao_cmd_put16
4. ao_cmd_put8
5. ao_cmd_white
6. ao_cmd_hex
7. ao_cmd_decimal
8. ao_match_word
9. ao_cmd_init

Chapter 9. Command line interface

Table of Contents

1. ao_cmd_register
2. ao_cmd_lex
3. ao_cmd_put16
4. ao_cmd_put8
5. ao_cmd_white
6. ao_cmd_hex
7. ao_cmd_decimal
8. ao_match_word
9. ao_cmd_init

AltOS includes a simple command line parser which is hooked up to the stdio interfaces permitting remote control of the device - over USB or the RF link as desired. Each command uses a single - character to invoke it, the remaining characters on the line are - available as parameters to the command. -

1. ao_cmd_register

+      over USB, serial or the RF link as desired. Each command uses a
+      single character to invoke it, the remaining characters on the
+      line are available as parameters to the command.
+    
1. ao_cmd_register
 	void
 	ao_cmd_register(__code struct ao_cmds *cmds)
       

@@ -452,49 +645,49 @@
 	'?' command. Syntax errors found while executing 'func'
 	should be indicated by modifying the global ao_cmd_status
 	variable with one of the following values:
-	

+	
ao_cmd_success

 		The command was parsed successfully. There is no
 		need to assign this value, it is the default.
-	      

+	      
ao_cmd_lex_error

 		A token in the line was invalid, such as a number
 		containing invalid characters. The low-level
 		lexing functions already assign this value as needed.
-	      

+	      
ao_syntax_error

 		The command line is invalid for some reason other
 		than invalid tokens.
 	      

-      
2. ao_cmd_lex
+      
2. ao_cmd_lex
 	void
 	ao_cmd_lex(void);
       

 	This gets the next character out of the command line
 	buffer and sticks it into ao_cmd_lex_c. At the end of the
 	line, ao_cmd_lex_c will get a newline ('\n') character.
-      
3. ao_cmd_put16
+      
3. ao_cmd_put16
 	void
 	ao_cmd_put16(uint16_t v);
       

 	Writes 'v' as four hexadecimal characters.
-      
4. ao_cmd_put8
+      
4. ao_cmd_put8
 	void
 	ao_cmd_put8(uint8_t v);
       

 	Writes 'v' as two hexadecimal characters.
-      
5. ao_cmd_white
+      
5. ao_cmd_white
 	void
 	ao_cmd_white(void)
       

 	This skips whitespace by calling ao_cmd_lex while
 	ao_cmd_lex_c is either a space or tab. It does not skip
 	any characters if ao_cmd_lex_c already non-white.
-      
6. ao_cmd_hex
+      
6. ao_cmd_hex
 	void
 	ao_cmd_hex(void)
       

 	This reads a 16-bit hexadecimal value from the command
 	line with optional leading whitespace. The resulting value
 	is stored in ao_cmd_lex_i;
-      
7. ao_cmd_decimal
+      
7. ao_cmd_decimal
 	void
 	ao_cmd_decimal(void)
       

@@ -502,7 +695,7 @@
 	line with optional leading whitespace. The resulting value
 	is stored in ao_cmd_lex_u32 and the low 16 bits are stored
 	in ao_cmd_lex_i;
-      
8. ao_match_word
+      
8. ao_match_word
 	uint8_t
 	ao_match_word(__code char *word)
       

@@ -510,15 +703,15 @@
 	line. It does not skip leading white space. If 'word' is
 	found, then 1 is returned. Otherwise, ao_cmd_status is set to
 	ao_cmd_syntax_error and 0 is returned.
-      
9. ao_cmd_init
+      
9. ao_cmd_init
 	void
 	ao_cmd_init(void
       

 	Initializes the command system, setting up the built-in
 	commands and adding a task to run the command processing
 	loop. It should be called by 'main' before ao_start_scheduler.
-      
Chapter 9. CC1111 USB target device
Table of Contents
1. ao_usb_flush
2. ao_usb_putchar
3. ao_usb_pollchar
4. ao_usb_getchar
5. ao_usb_disable
6. ao_usb_enable
7. ao_usb_init

-      The CC1111 contains a full-speed USB target device. It can be
+

Chapter 10. USB target device

Table of Contents

1. ao_usb_flush
2. ao_usb_putchar
3. ao_usb_pollchar
4. ao_usb_getchar
5. ao_usb_disable
6. ao_usb_enable
7. ao_usb_init

+ AltOS contains a full-speed USB target device driver. It can be programmed to offer any kind of USB target, but to simplify interactions with a variety of operating systems, AltOS provides only a single target device profile, that of a USB modem which @@ -531,7 +724,7 @@ interface if desired, offering control of the device over the USB link. Alternatively, the functions can be accessed directly to provide for USB-specific I/O. -

1. ao_usb_flush

+    
1. ao_usb_flush
 	void
 	ao_usb_flush(void);
       

@@ -539,7 +732,7 @@
 	to be delivered to the USB host if there is pending data,
 	or if the last IN packet was full to indicate to the host
 	that there isn't any more pending data available.
-      
2. ao_usb_putchar
+      
2. ao_usb_putchar
 	void
 	ao_usb_putchar(char c);
       

@@ -548,7 +741,7 @@
 	adds a byte to the pending IN packet for delivery to the
 	USB host. If the USB packet is full, this queues the 'IN'
 	packet for delivery.
-      
3. ao_usb_pollchar
+      
3. ao_usb_pollchar
 	char
 	ao_usb_pollchar(void);
       

@@ -556,13 +749,13 @@
 	packet received, this returns AO_READ_AGAIN. Otherwise, it
 	returns the next character, reporting to the host that it
 	is ready for more data when the last character is gone.
-      
4. ao_usb_getchar
+      
4. ao_usb_getchar
 	char
 	ao_usb_getchar(void);
       

 	This uses ao_pollchar to receive the next character,
 	blocking while ao_pollchar returns AO_READ_AGAIN.
-      
5. ao_usb_disable
+      
5. ao_usb_disable
 	void
 	ao_usb_disable(void);
       

@@ -577,7 +770,7 @@
 	after disabling the USB device, it's likely that the cable
 	will need to be disconnected and reconnected before it
 	will work again.
-      
6. ao_usb_enable
+      
6. ao_usb_enable
 	void
 	ao_usb_enable(void);
       

@@ -585,7 +778,7 @@
 	disabled. See the note above about needing to physically
 	remove and re-insert the cable to get the host to
 	re-initialize the USB link.
-      
7. ao_usb_init
+      
7. ao_usb_init
 	void
 	ao_usb_init(void);
       

@@ -593,7 +786,7 @@
 	the control end point and adds the usb I/O functions to
 	the stdio system. Call this from main before
 	ao_start_scheduler.
-

Chapter 10. CC1111 Serial peripheral

Table of Contents

1. ao_serial_getchar
2. ao_serial_putchar
3. ao_serial_drain
4. ao_serial_set_speed
5. ao_serial_init

Chapter 11. Serial peripherals

Table of Contents

1. ao_serial_getchar
2. ao_serial_putchar
3. ao_serial_drain
4. ao_serial_set_speed
5. ao_serial_init

The CC1111 provides two USART peripherals. AltOS uses one for asynch serial data, generally to communicate with a GPS device, and the other for a SPI bus. The UART is configured to operate @@ -604,25 +797,25 @@

To prevent loss of data, AltOS provides receive and transmit fifos of 32 characters each. -

1. ao_serial_getchar

+    
1. ao_serial_getchar
 	char
 	ao_serial_getchar(void);
       

 	Returns the next character from the receive fifo, blocking
 	until a character is received if the fifo is empty.
-      
2. ao_serial_putchar
+      
2. ao_serial_putchar
 	void
 	ao_serial_putchar(char c);
       

 	Adds a character to the transmit fifo, blocking if the
 	fifo is full. Starts transmitting characters.
-      
3. ao_serial_drain
+      
3. ao_serial_drain
 	void
 	ao_serial_drain(void);
       

 	Blocks until the transmit fifo is empty. Used internally
 	when changing serial speeds.
-      
4. ao_serial_set_speed
+      
4. ao_serial_set_speed
 	void
 	ao_serial_set_speed(uint8_t speed);
       

@@ -630,52 +823,52 @@
 	AO_SERIAL_SPEED_4800, AO_SERIAL_SPEED_9600 or
 	AO_SERIAL_SPEED_57600. This first flushes the transmit
 	fifo using ao_serial_drain.
-      
5. ao_serial_init
+      
5. ao_serial_init
 	void
 	ao_serial_init(void)
       

 	Initializes the serial peripheral. Call this from 'main'
 	before jumping to ao_start_scheduler. The default speed
 	setting is AO_SERIAL_SPEED_4800.
-

Chapter 11. CC1111 Radio peripheral

Table of Contents

1. ao_radio_set_telemetry
2. ao_radio_set_packet
3. ao_radio_set_rdf
4. ao_radio_idle
5. ao_radio_get
6. ao_radio_put
7. ao_radio_abort
8. ao_radio_send
9. ao_radio_recv
10. ao_radio_rdf
11. ao_packet_putchar
12. ao_packet_pollchar
13. ao_packet_slave_start
14. ao_packet_slave_stop
15. ao_packet_slave_init
16. ao_packet_master_init

- The CC1111 radio transceiver sends and receives digital packets - with forward error correction and detection. The AltOS driver is - fairly specific to the needs of the TeleMetrum and TeleDongle - devices, using it for other tasks may require customization of - the driver itself. There are three basic modes of operation: -

- Telemetry mode. In this mode, TeleMetrum transmits telemetry - frames at a fixed rate. The frames are of fixed size. This - is strictly a one-way communication from TeleMetrum to - TeleDongle. -
- Packet mode. In this mode, the radio is used to create a - reliable duplex byte stream between TeleDongle and - TeleMetrum. This is an asymmetrical protocol with - TeleMetrum only transmitting in response to a packet sent - from TeleDongle. Thus getting data from TeleMetrum to - TeleDongle requires polling. The polling rate is adaptive, - when no data has been received for a while, the rate slows - down. The packets are checked at both ends and invalid - data are ignored. -
- On the TeleMetrum side, the packet link is hooked into the - stdio mechanism, providing an alternate data path for the - command processor. It is enabled when the unit boots up in - 'idle' mode. -
- On the TeleDongle side, the packet link is enabled with a - command; data from the stdio package is forwarded over the - packet link providing a connection from the USB command - stream to the remote TeleMetrum device. -
- Radio Direction Finding mode. In this mode, TeleMetrum - constructs a special packet that sounds like an audio tone - when received by a conventional narrow-band FM - receiver. This is designed to provide a beacon to track - the device when other location mechanisms fail. -

1. ao_radio_set_telemetry

Chapter 12. CC1111 Radio peripheral

1. Radio Introduction

+ The CC1111 radio transceiver sends and receives digital packets + with forward error correction and detection. The AltOS driver is + fairly specific to the needs of the TeleMetrum and TeleDongle + devices, using it for other tasks may require customization of + the driver itself. There are three basic modes of operation: +

+ Telemetry mode. In this mode, TeleMetrum transmits telemetry + frames at a fixed rate. The frames are of fixed size. This + is strictly a one-way communication from TeleMetrum to + TeleDongle. +
+ Packet mode. In this mode, the radio is used to create a + reliable duplex byte stream between TeleDongle and + TeleMetrum. This is an asymmetrical protocol with + TeleMetrum only transmitting in response to a packet sent + from TeleDongle. Thus getting data from TeleMetrum to + TeleDongle requires polling. The polling rate is adaptive, + when no data has been received for a while, the rate slows + down. The packets are checked at both ends and invalid + data are ignored. +
+ On the TeleMetrum side, the packet link is hooked into the + stdio mechanism, providing an alternate data path for the + command processor. It is enabled when the unit boots up in + 'idle' mode. +
+ On the TeleDongle side, the packet link is enabled with a + command; data from the stdio package is forwarded over the + packet link providing a connection from the USB command + stream to the remote TeleMetrum device. +
+ Radio Direction Finding mode. In this mode, TeleMetrum + constructs a special packet that sounds like an audio tone + when received by a conventional narrow-band FM + receiver. This is designed to provide a beacon to track + the device when other location mechanisms fail. +

2. ao_radio_set_telemetry

 	  void
 	  ao_radio_set_telemetry(void);

@@ -684,7 +877,7 @@ other RF parameters. It does not include the base frequency or channel though. Those are set at the time of transmission or reception, in case the values are changed by the user. -

2. ao_radio_set_packet

3. ao_radio_set_packet

 	  void
 	  ao_radio_set_packet(void);

@@ -693,7 +886,7 @@ parameters. It does not include the base frequency or channel though. Those are set at the time of transmission or reception, in case the values are changed by the user. -

3. ao_radio_set_rdf

4. ao_radio_set_rdf

 	  void
 	  ao_radio_set_rdf(void);

@@ -703,38 +896,38 @@ and data whitening logic is turned off so that the resulting modulation is received as a 1kHz tone by a conventional 70cm FM audio receiver. -

4. ao_radio_idle

5. ao_radio_idle

 	  void
 	  ao_radio_idle(void);

Sets the radio device to idle mode, waiting until it reaches that state. This will terminate any in-progress transmit or receive operation. -

5. ao_radio_get

6. ao_radio_get

 	  void
 	  ao_radio_get(void);

Acquires the radio mutex and then configures the radio frequency using the global radio calibration and channel values. -

6. ao_radio_put

7. ao_radio_put

 	  void
 	  ao_radio_put(void);

Releases the radio mutex. -

7. ao_radio_abort

8. ao_radio_abort

 	  void
 	  ao_radio_abort(void);

Aborts any transmission or reception process by aborting the associated DMA object and calling ao_radio_idle to terminate the radio operation. -

- In telemetry mode, you can send or receive a telemetry - packet. The data from receiving a packet also includes the RSSI - and status values supplied by the receiver. These are added - after the telemetry data. -

8. ao_radio_send

9. Radio Telemetry

+ In telemetry mode, you can send or receive a telemetry + packet. The data from receiving a packet also includes the RSSI + and status values supplied by the receiver. These are added + after the telemetry data. +

9.1. ao_radio_send

 	  void
 	  ao_radio_send(__xdata struct ao_telemetry *telemetry);

@@ -743,7 +936,7 @@ telemetry mode. This function calls ao_radio_get() before sending, and ao_radio_put() afterwards, to correctly serialize access to the radio device. -

9. ao_radio_recv

9.2. ao_radio_recv

 	  void
 	  ao_radio_recv(__xdata struct ao_radio_recv *radio);

@@ -754,21 +947,21 @@ to the radio device. This returns non-zero if a packet was received, or zero if the operation was aborted (from some other task calling ao_radio_abort()). -

- In radio direction finding mode, there's just one function to - use -

10. ao_radio_rdf

10. Radio Direction Finding

+ In radio direction finding mode, there's just one function to + use +

10.1. ao_radio_rdf

 	  void
 	  ao_radio_rdf(int ms);

This sends an RDF packet lasting for the specified amount of time. The maximum length is 1020 ms. -

- Packet mode is asymmetrical and is configured at compile time - for either master or slave mode (but not both). The basic I/O - functions look the same at both ends, but the internals are - different, along with the initialization steps. -

11. ao_packet_putchar

11. Radio Packet Mode

+ Packet mode is asymmetrical and is configured at compile time + for either master or slave mode (but not both). The basic I/O + functions look the same at both ends, but the internals are + different, along with the initialization steps. +

11.1. ao_packet_putchar

 	  void
 	  ao_packet_putchar(char c);

@@ -778,34 +971,34 @@ transmit a packet if the output buffer is full. On the slave side, any pending data will be sent the next time the master polls for data. -

12. ao_packet_pollchar

11.2. ao_packet_pollchar

 	  char
 	  ao_packet_pollchar(void);

This returns a pending input character if available, otherwise returns AO_READ_AGAIN. On the master side, if this empties the buffer, it triggers a poll for more data. -

13. ao_packet_slave_start

11.3. ao_packet_slave_start

 	  void
 	  ao_packet_slave_start(void);

This is available only on the slave side and starts a task to listen for packet data. -

14. ao_packet_slave_stop

11.4. ao_packet_slave_stop

 	  void
 	  ao_packet_slave_stop(void);

Disables the packet slave task, stopping the radio receiver. -

15. ao_packet_slave_init

11.5. ao_packet_slave_init

 	  void
 	  ao_packet_slave_init(void);

Adds the packet stdio functions to the stdio package so that when packet slave mode is enabled, characters will get send and received through the stdio functions. -

16. ao_packet_master_init

11.6. ao_packet_master_init

 	  void
 	  ao_packet_master_init(void);

Adds the 'p' packet forward command to start packet mode. -

-- cgit v1.2.3

AltOS

Altos Metrum Operating System

Keith Packard

AltOS

Altos Metrum Operating System

Keith Packard

Chapter 1. Overview

Chapter 1. Overview

Chapter 2. Programming the 8051 with SDCC

Chapter 2. AltOS Porting Layer

1. Low-level CPU operations

1.1. ao_arch_block_interrupts/ao_arch_release_interrupts

1.2. ao_arch_save_regs, ao_arch_save_stack, + ao_arch_restore_stack

1.3. ao_arch_wait_interupt

2. GPIO operations

2.1. GPIO setup

2.1.1. ao_enable_output

2.1.2. ao_enable_input

2.2. Reading and writing GPIO pins

2.2.1. ao_gpio_set

2.2.2. ao_gpio_get

Chapter 3. Programming the 8051 with SDCC

1. 8051 memory spaces

1. 8051 memory spaces

1.1. __data

1.1. __data

1.2. __idata

1.2. __idata

1.3. __xdata

1.3. __xdata

1.4. __pdata

1.4. __pdata

1.5. __code

1.5. __code

1.6. __bit

1.6. __bit

1.7. __sfr, __sfr16, __sfr32, __sbit

1.7. __sfr, __sfr16, __sfr32, __sbit

2. Function calls on the 8051

2. Function calls on the 8051

2.1. __reentrant functions

2.1. __reentrant functions

2.2. Non __reentrant functions

2.2. Non __reentrant functions

2.3. __interrupt functions

2.3. __interrupt functions

2.4. __critical functions and statements

2.4. __critical functions and statements

Chapter 3. Task functions

Chapter 4. Task functions

1. ao_add_task

1. ao_add_task

2. ao_exit

2. ao_exit

3. ao_sleep

3. ao_sleep

4. ao_wakeup

4. ao_wakeup

5. ao_alarm

5. ao_alarm

6. ao_start_scheduler

6. ao_start_scheduler

7. ao_clock_init

7. ao_clock_init

Chapter 4. Timer Functions

Chapter 5. Timer Functions

1. ao_time

1. ao_time

2. ao_delay

2. ao_delay

3. ao_timer_set_adc_interval

3. ao_timer_set_adc_interval

4. ao_timer_init

4. ao_timer_init

Chapter 5. AltOS Mutexes

Chapter 6. AltOS Mutexes

1. ao_mutex_get

1. ao_mutex_get

2. ao_mutex_put

2. ao_mutex_put

1.7. sfr, sfr16, sfr32, sbit

1.7. sfr, sfr16, sfr32, sbit