RS5C348_REG_HOURS
tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
txp[RS5C348_REG_HOURS] = bin2bcd(tm->tm_hour);
txp[RS5C348_REG_HOURS] = bin2bcd((tm->tm_hour + 11) % 12 + 1) |