河北水利局项目

yw/crc.c

@@ -0,0 +1,47 @@
+#include "stdafx.h"
+#include "crc.h"
+/*
+static u16 crc16(unsigned char *buf,unsigned short length)
+{  
+	int i = 0;
+	int j = 0;
+	int crc16 = 0xffff;
+	for (i = 0;i < length;i++)
+	{
+		crc16 = crc16 ^ buf[i];
+		for (j = 0;j < 8;j++)
+		{
+			if (crc16 & 0x01)
+			{
+				crc16 = (crc16 >> 1) ^ 0xa001;
+			}
+			else 
+			{
+				crc16 = crc16 >> 1;
+			}
+		}
+	}
+	return (u16)crc16;
+}
+*/
+
+static unsigned int cal_crc16(unsigned char *ptr, unsigned int len) 
+{ 
+ unsigned int crc; 
+ unsigned char i; 
+ crc=0xffff; 
+ while(len--!=0) { 
+ crc = crc^(*ptr); 
+ for(i=0; i<8; i++) { 
+ if((crc&0x0001)==0x0001) {crc>>=1;crc^=0xA001;} 
+ else crc>>=1; 
+ } 
+ ptr++; 
+} 
+return(crc); 
+}
+u16 get_crc(u8 * val,u16 len)
+{
+	return cal_crc16(val,len);
+}
+