MSP430F2012: MSP430F2012 in 4 pin SPI mode

Jan Volkering

Part Number: MSP430F2012

Hi,

I intend to use a small MSP430F2012 to read out a DC potmeter value and transmit that over a SPI in slave mode.

Since I have one SPI master and a total of four SPI slaves in my system I want to use the STE pin to disable the MSP430F2012 when the other SPI slaves are addressed.

The MSP430Fx2xx Family Users guide indicates 4 pin SPI mode is possible on the MSP430F2012 but the datasheet doesn't show the STE pin availability.

Can you explain if 4 pin SPI slave mode is possible on the MSP430F2012 or not and if so, which pin is assigned to the SPI-STE pin.

Regards.

over 5 years ago

0 James Evans over 5 years ago

TI__Mastermind 49692 points

Hello,

Thanks for your detailed post. The MSP430F2012 features a USI module, not a USCI module. According to the MSP430x2xx Family User's Guide, devices with the USI module only support 3-wire SPI whereas devices with the USCI module support both 3-wire and 4-wire SPI.

Have you heard about our newer MSP430 FRAM devices? Check out the SPI I/O Expander Using Low-Memory MSP430™ MCUs based on the MSP430FR2000 MCU Tech Note. In Figure 1 of this Tech Note, I see the slave select (STE) pin is being used. Perhaps, combining the code from this Tech Note and code from our other code examples would help get you started!