X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;ds=sidebyside;f=bertos%2Falgo%2Fcrc.h;h=b64d140feb16adcb33f002120d16cbf35661b19b;hb=fa680c1a4d8250aee2ad4dd46a833b0279c7e9de;hp=be8f0df8be16915f3318852f3329f2bda9e70fc1;hpb=37efb5bdc0504ab6df2e8db0635c9c6f7477e23e;p=bertos.git

diff --git a/bertos/algo/crc.h b/bertos/algo/crc.h
index be8f0df8..b64d140f 100644
--- a/bertos/algo/crc.h
+++ b/bertos/algo/crc.h
@@ -31,7 +31,7 @@
  *
  * -->
  *
- * \brief Cyclic Redundancy Check 16 (CRC).
+ * \brief Cyclic Redundancy Check 16 (CRC). This algorithm is the one used by the XMODEM protocol.
  *
  * \note This algorithm is incompatible with the CCITT-CRC16.
  *
@@ -53,11 +53,9 @@
 #define ALGO_CRC_H
 
 #include <cfg/compiler.h>
+#include <cpu/pgm.h>
 
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
+EXTERN_C_BEGIN
 
 /* CRC table */
 extern const uint16_t crc16tab[256];
@@ -72,16 +70,26 @@ extern const uint16_t crc16tab[256];
  * \param c New octet (range 0-255)
  * \param oldcrc Previous CRC16 value (referenced twice, beware of side effects)
  */
-#define UPDCRC16(c, oldcrc) (crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))] ^ ((oldcrc) << 8))
+#if CPU_HARVARD
+	#define UPDCRC16(c, oldcrc) (pgm_read_uint16_t(&crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
+#else
+	#define UPDCRC16(c, oldcrc) ((crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
+#endif
 
+/** CRC-16 init value */
+#define CRC16_INIT_VAL ((uint16_t)0)
 
 #ifdef INLINE
 /**
- * \brief Compute the updated CRC16 value for one octet (macro version)
+ * \brief Compute the updated CRC16 value for one octet (inline version)
  */
 INLINE uint16_t updcrc16(uint8_t c, uint16_t oldcrc)
 {
+#if CPU_HARVARD
+	return pgm_read_uint16_t(&crc16tab[(oldcrc >> 8) ^ c]) ^ (oldcrc << 8);
+#else
 	return crc16tab[(oldcrc >> 8) ^ c] ^ (oldcrc << 8);
+#endif
 }
 #endif // INLINE
 
@@ -97,8 +105,6 @@ INLINE uint16_t updcrc16(uint8_t c, uint16_t oldcrc)
  */
 extern uint16_t crc16(uint16_t crc, const void *buf, size_t len);
 
-#ifdef __cplusplus
-}
-#endif /* __cplusplus */
+EXTERN_C_END
 
 #endif /* ALGO_CRC_H */