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Transport CRC will not use table in UAVCAN_TINY builds

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This commit is contained in:
Pavel Kirienko
2014-04-16 17:19:05 +04:00
parent f8b10ab003
commit a298ad9ba2
2 changed files with 25 additions and 1 deletions
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libuavcan/include/uavcan/transport/crc.hpp
+21
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@@ -26,7 +26,10 @@ namespace uavcan
*/
class UAVCAN_EXPORT TransferCRC
{
#if !UAVCAN_TINY
static const uint16_t Table[256];
#endif
uint16_t value_;
public:
@@ -36,10 +39,28 @@ public:
: value_(0xFFFF)
{ }
#if UAVCAN_TINY
void add(uint8_t byte)
{
value_ ^= byte << 8;
for (uint8_t bit = 8; bit > 0; --bit)
{
if (value_ & 0x8000)
{
value_ = (value_ << 1) ^ 0x1021;
}
else
{
value_ = (value_ << 1);
}
}
}
#else
void add(uint8_t byte)
{
value_ = ((value_ << 8) ^ Table[((value_ >> 8) ^ byte) & 0xFF]) & 0xFFFF;
}
#endif
void add(const uint8_t* bytes, unsigned len)
{