I'm using an ADuC831 with an SPI connected RTC and memory chip. I have not been able to get the clock and data lines to both be low during the power down mode (low current sleep). If I leave it in SPI mode, I can get the clock to go low with CPOL=0, but the data line always stays high. If I go to I2C mode before the power down command, I can get the data line to go low, but the clock always stays high. I must be missing something simple, but I'm just not seeing it. How can I get both lines to be low during the low power sleep?
Any other docs or suggestions for low power sleep operation would be appreciated as well.