SCPDR_TP_SCAN_Y
scpdr &= ~SCPDR_TP_SCAN_Y; /* pull low to scan */
scpdr |= SCPDR_TP_SCAN_Y;
scpdr |= (SCPDR_TP_SCAN_ENABLE | SCPDR_TP_SCAN_Y);
scpdr &= ~(SCPDR_TP_SCAN_ENABLE | SCPDR_TP_SCAN_Y);