OVERRUN
if (rx_status & (ABORT|OVERRUN|TOOLONG|RUNT|RXISERR|CRCERR|FAERR)) {
s |= OVERRUN;
#define S_ERRORS (PERROR|OVERRUN|FRERROR)
s |= OVERRUN;
#define S_ERRORS (PERROR|OVERRUN|FRERROR)