diff options
| author | Keith Packard <keithp@keithp.com> | 2017-01-22 15:29:13 -0800 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2017-02-20 11:16:52 -0800 |
| commit | d96224c2fdc535d08de23aec30d62d4ada9fb8d3 (patch) | |
| tree | 9172440e8b576a4427556a8d9f129c1650887244 | |
| parent | bc076747f6cc00508aef909a3a5bd3edf8c9bd66 (diff) | |
altos/chaoskey: use both halves of the CRC
When pulling 16 bits from the 32-bit crc, instead of just using the
low bits, xor the two halves together. This appears to even out the
number of zero and one bits.
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | src/chaoskey-v1.0/Makefile | 1 | ||||
| -rw-r--r-- | src/stmf0/ao_crc.h | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/src/chaoskey-v1.0/Makefile b/src/chaoskey-v1.0/Makefile index f6b78d07..f2c168ba 100644 --- a/src/chaoskey-v1.0/Makefile +++ b/src/chaoskey-v1.0/Makefile @@ -14,6 +14,7 @@ INC = \ ao_task.h \ ao_adc_fast.h \ ao_power.h \ + ao_crc.h \ stm32f0.h # diff --git a/src/stmf0/ao_crc.h b/src/stmf0/ao_crc.h index 7acc6f9c..b6d91023 100644 --- a/src/stmf0/ao_crc.h +++ b/src/stmf0/ao_crc.h @@ -35,7 +35,8 @@ static inline uint16_t ao_crc_in_32_out_16(uint32_t v) { stm_crc.dr.u32 = v; - return stm_crc.dr.u16; + v = stm_crc.dr.u32; + return v ^ (v >> 16); } static inline uint16_t |