How to save power when SPI bus is not active?

[veraleh]

Hello All,

I have 2 MSP430 connected via an SPI bus, one is a master and the other is a slave.
The SPI bus is not working all the time, and I have an interrupt line to signal from the Master to the Slave when to start the SPI (configure the port).

I manage to reduce power consumption (about 80uA at each side) by setting the SPI logic to RESET (in the USCI module it is simply by setting

   UCB0CTL1 |= UCSWRST;

Will I save MORE power if I reset the ports to input?

   P3SEL &= ~0x0E; P3DIR &= ~0x0E;

I don't have a sensitive current measurement tool to answer this question.

Ohad.