ti_do_config
status = ti_do_config(port, UMPC_SET_CLR_DTR, mcr & MCR_DTR);
status = ti_do_config(port, UMPC_SET_CLR_RTS, mcr & MCR_RTS);
return ti_do_config(port, UMPC_SET_CLR_LOOPBACK, mcr & MCR_LOOPBACK);
status = ti_do_config(edge_port, UMPC_SET_CLR_LOOPBACK, 0);
status = ti_do_config(edge_port, UMPC_SET_CLR_BREAK, bv);