ttl_write_reg
ttl_write_reg(mod, PORTA_IOCTL, 0x00ff);
ttl_write_reg(mod, PORTB_IOCTL, 0x00ff);
ttl_write_reg(mod, PORTC_IOCTL, 0x000f);
ttl_write_reg(mod, PORTA_DIRECTION, 0x0000);
ttl_write_reg(mod, PORTB_DIRECTION, 0x0000);
ttl_write_reg(mod, PORTC_DIRECTION, 0x0000);
ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE);