com_cfcr
outb(comc_port + com_cfcr, CFCR_DLAB | COMC_FMT);
outb(comc_port + com_cfcr, COMC_FMT);
cfcr = inb(comc_port + com_cfcr);
outb(comc_port + com_cfcr, CFCR_DLAB | cfcr);
outb(comc_port + com_cfcr, cfcr);