_NSECT
CSR_WRITE_1(chan->cmd + _NSECT, 0);
CSR_WRITE_1(chan->cmd + _NSECT, 0);
return CSR_READ_1(chan->cmd + _NSECT);
CSR_WRITE_1(chan->cmd + _NSECT, XFER_PIO0);
CSR_WRITE_1(chan->cmd + _NSECT, 0); /* always less than 256 */
CSR_WRITE_1(chan->cmd + _NSECT, nblk);
CSR_WRITE_1(chan->cmd + _NSECT, nblk);