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author | jaseg <git@jaseg.net> | 2019-04-14 13:25:23 +0900 |
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committer | jaseg <git@jaseg.net> | 2019-04-14 13:25:23 +0900 |
commit | 668c89f88988e4bd6149fa7d13650254037f028d (patch) | |
tree | dbd2188c7f15fd2756de1e5d79b9ce569c0f4cd4 /driver_fw/mac.h | |
parent | 010d5587b776030690a2ab25902fe9eff52fcf5b (diff) | |
download | 8seg-668c89f88988e4bd6149fa7d13650254037f028d.tar.gz 8seg-668c89f88988e4bd6149fa7d13650254037f028d.tar.bz2 8seg-668c89f88988e4bd6149fa7d13650254037f028d.zip |
driver/fw: I2C LCD working
Diffstat (limited to 'driver_fw/mac.h')
-rw-r--r-- | driver_fw/mac.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/driver_fw/mac.h b/driver_fw/mac.h new file mode 100644 index 0000000..26aaff6 --- /dev/null +++ b/driver_fw/mac.h @@ -0,0 +1,22 @@ +#ifndef __MAC_H__ +#define __MAC_H__ + +#include <unistd.h> + +/* Device MAC address. + * + * 32 bits might seem a little short for a device MAC, but at 20 bus nodes the probablility of a collision is about 1 in + * 10 million. Check for yourself using the python code below. + * + * #!/usr/bin/env python3 + * from operator import mul + * from functools import reduce + * m = 32 + * n = 20 + * print(reduce(mul, [2**m-i for i in range(n)]) / ((2**m)**n)) + * # -> 0.9999999557621786 + */ + +extern uint32_t device_mac; + +#endif /* __MAC_H__ */ |