INTF_TBE
if (ireq & INTF_TBE) {
custom.intreq = INTF_TBE;
custom.intreq = INTF_SETCLR | INTF_TBE;
custom.intena = INTF_RBF | INTF_TBE; /* disable interrupts */
custom.intreq = INTF_RBF | INTF_TBE; /* clear intr request */
custom.intreq = INTF_SETCLR | INTF_TBE;
custom.intreq = INTF_SETCLR | INTF_TBE;
custom.intena = INTF_SETCLR | INTF_RBF | INTF_TBE;
if ((custom.intreqr & INTF_TBE) == 0)
custom.intreq = INTF_TBE;
if (ireq & INTF_TBE) {
custom.intreq = INTF_TBE;