RS5C348_REG_MONTH
bcd2bin(rxbuf[RS5C348_REG_MONTH] & RS5C348_MONTH_MASK) - 1;
((rxbuf[RS5C348_REG_MONTH] & RS5C348_BIT_Y2K) ? 100 : 0);
txp[RS5C348_REG_MONTH] = bin2bcd(tm->tm_mon + 1) |