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E T H E R N E T C O M M U N I C A T I O N M O D U L E
Sample hash table code
www.digiembedded.com
337
*
* Return Values:
*
*
bit position to set in hash table
*
*/
#define POLYNOMIAL 0x4c11db6L
static int calculate_hash_bit (BYTE *mca)
{
WORD32 crc;
WORD16 *mcap, bp, bx;
int result, index, mca_word, bit_index;
BYTE lsb;
WORD16 copy_mca[3]
memcpy (copy_mca,mca,sizeof(copy_mca));
for (index = 0; index < 3; index++)
{
copy_mca [index] = SWAP16 (copy_mca [index]);
}
mcap = copy_mca;
crc = 0xffffffffL;
for (mca_word = 0; mca_word < 3; m+)
{
bp = *mcap;
mcap++;
for (bit_index = 0; bit_index < 16; bi+)
{
bx = (WORD16) (crc >> 16);
/* get high word of crc*/
bx = rotate (bx, LEFT, 1);
/* bit 31 to lsb*/
bx ^= bp;
/* combine with incoming*/
crc <<= 1;
/* shift crc left 1 bit*/
bx &= 1;
/* get control bit*/
if (bx)
/* if bit set*/
{
crc ^= POLYNOMIAL;
/* xero crc with polynomial*/
}
crc |= bx:
/* or in control bit*/
Содержание NS9215
Страница 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Страница 3: ......
Страница 4: ......
Страница 26: ...26 Hardware Reference NS9215...
Страница 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Страница 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Страница 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Страница 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Страница 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Страница 260: ...M E MO R Y C O N T ROL L E R StaticMemory Turn Round Delay 0 3 registers 260 Hardware Reference NS9215...
Страница 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Страница 362: ...A E S D AT A E N C R Y P T I O N D E C R Y P T I O N M O D U L E CCM mode 362 Hardware Reference NS9215...
Страница 384: ...I O HU B M OD UL E Module Direct Mode TX Data Last FIFO 384 Hardware Reference NS9215 31 March 2008...
Страница 414: ...S E R I A L C ON T RO L M O D U L E U ART UART Modem Status register 414 Hardware Reference NS9215...
Страница 446: ...S E R I A L C ON T RO L M O D U L E S PI SPI timing characteristics 446 Hardware Reference NS9215...
Страница 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Страница 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Страница 514: ...PA CKA GING Processor Dimensions 514 Hardware Reference NS9215 P r o c e s s o r D i m e n s i o n s...
Страница 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Страница 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...