int main(void)
{
int i, j;
unsigned short CRC_Xmit;
unsigned short CRC_Recv;
int Detected_Count = 0;
int Okay_Count = 0;
/* Initialize. */
for (i = 0; i < 1024; i++) {
Raw_Data[i] = (unsigned char)i;
}
CRC_Xmit = CRC_Clear();
Initialize_Noise(1.0e-5);
/* Compute the CRC checksum. */
for (i = 0; i < 1024; i++) {
CRC_Xmit = CRC_Update(CRC_Xmit, Raw_Data[i]);
}
CRC_Xmit = CRC_Finish(CRC_Xmit);
/* Now loop many times sending the block of data through the channel. */
for (i = 0; i < 1024; i++) {
CRC_Recv = CRC_Clear();
for (j = 0; j < 1024; j++) {
CRC_Recv = CRC_Update(CRC_Recv, Channel(Raw_Data[j]));
}
CRC_Recv = CRC_Update(CRC_Recv, Channel((CRC_Xmit & 0xFF00) >> 8));
CRC_Recv = CRC_Update(CRC_Recv, Channel(CRC_Xmit & 0x00FF));
if (CRC_Recv != 0) Detected_Count++;
else Okay_Count++;
}
printf("Blocks with detected errors: %d\n", Detected_Count);
printf("Blocks okay: %d\n", Okay_Count);
return 0;
}
dsk_err_t w32serial_call(DSK_PDRIVER pDriver, unsigned char *input,
int inp_len, unsigned char *output, int *out_len)
{
word16 wire_len;
word16 crc;
byte var;
byte wvar[2];
int n;
dsk_err_t err;
unsigned char *tmpbuf;
W32SERIAL_REMOTE_DATA *self = (W32SERIAL_REMOTE_DATA *)pDriver->dr_remote;
if (!self || self->super.rd_class != &rpc_w32serial) return DSK_ERR_BADPTR;
/* CRC tbe input... */
wire_len = inp_len;
CRC_Clear();
for (n = 0; n < inp_len; n++) CRC_Update(input[n]);
crc = CRC_Done();
/*
printf("rpc_w32serial: Input packet: ");
for (n = 0; n < inp_len; n++) printf("%02x ", input[n]);
printf("\n");
*/
while (1)
{
/* Write SOH (start of request) */
err = wrbyte(self, SOH); if (err) return err;
/* Write packet length (network byte order) */
wvar[0] = wire_len >> 8;
wvar[1] = wire_len & 0xFF;
err = write_bytes(self, 2, wvar);
if (err) return err;
err = write_bytes(self, inp_len, input);
if (err) return err;
wvar[0] = crc >> 8;
wvar[1] = crc & 0xFF;
err = write_bytes(self, 2, wvar);
if (err) return err;
/*
err = read_bytes(self, 1, &var); if (err) return err;
*/
/* Wait 'til we get an ACK or a NAK. */
do
{
err = read_bytes(self, 1, &var);
if (err) return err;
}
while(var != ACK && var != NAK);
if (var == ACK) break;
if (var == NAK) continue;
}
/* Outgoing packet sent. Await response */
while (1)
{
/* First byte of response must be STX. */
err = read_bytes(self, 1, &var); if (err) return err;
if (var != STX) continue;
err = read_bytes(self, 2, wvar); if (err) return err;
wire_len = wvar[0];
wire_len = (wire_len << 8) | wvar[1];
tmpbuf = dsk_malloc(wire_len + 2);
if (!tmpbuf) return DSK_ERR_NOMEM;
CRC_Clear();
err = read_bytes(self, wire_len + 2, tmpbuf);
if (err) { dsk_free(tmpbuf); return err; }
for (n = 0; n < wire_len; n++)
{
CRC_Update(tmpbuf[n]);
}
crc = tmpbuf[wire_len];
crc = (crc << 8) | tmpbuf[wire_len + 1];
/* If CRC matches, send ACK and return. Else send NAK. */
if (crc == CRC_Done())
{
/*
printf("rpc_w32serial: Result packet: ");
for (n = 0; n < wire_len; n++) printf("%02x ", tmpbuf[n]);
printf("\n");
*/
err = wrbyte(self, ACK);
if (err) { dsk_free(tmpbuf); return err; }
/* Copy packet to waiting output buffer */
if (wire_len < *out_len) *out_len = wire_len;
memcpy(output, tmpbuf, *out_len);
dsk_free(tmpbuf);
return DSK_ERR_OK;
}
/* Packet was garbled. NAK it and try again. */
dsk_free(tmpbuf);
err = wrbyte(self, NAK);
if (err) return err;
}
/* Should never happen */
return DSK_ERR_NOTIMPL;
}