XMTFWU
out_8(&mb->fifocc, RCVFW_32 | XMTFW_16 | XMTFWU | RCVFWU | XMTBRST);
out_8(&mb->fifocc, in_8(&mb->fifocc) | XMTFWU);
mb->fifocc = XMTFW_8 | RCVFW_64 | XMTFWU | RCVFWU;