MCS7840_UART_ISR_INTMASK
DPRINTF("Port %d has pending interrupt: %02x (FIFO: %02x)\n", pn, buf[pn] & MCS7840_UART_ISR_INTMASK, buf[pn] & (~MCS7840_UART_ISR_INTMASK));
switch (buf[pn] & MCS7840_UART_ISR_INTMASK) {