RV3029_A_DW
tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)