PCF_SET_S1
PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK);
PCF_SET_S1(pcf, ES0|STA|STO|ACK);
PCF_SET_S1(pcf, PIN|ES0|STA|ACK);
PCF_SET_S1(pcf, PIN|ES0|ENI|ACK);
PCF_SET_S1(pcf, PIN); /* initialize S1 */
PCF_SET_S1(pcf, PIN|ES1);
PCF_SET_S1(pcf, PIN|ES0|ENI|ACK);
PCF_SET_S1(pcf, ES0); /* no ack */
PCF_SET_S1(pcf, ES0);