SPI SPISTE pin as GPIO on 28069 Piccolo

Unfortunately, no.  The SPI module on the TMS320F28069 supports 4-wire and 3-wire modes of operation, but in 3-wire, the data lines (input and output) are shared and SPISTE is still used for the slave.

Mark,

If the slave does not need to send data you can do this.  The SPISTEn signal is what allows the slave to reply to the master.  Unfortunately it has no way of knowing it is the only one on the chain.

Kris

Kris,

Thank you for replay. F28069 (slave) needs to replay to master query. We are short on GPIO's so I'm looking for a way to have slave enabled all

the time (it is the only slave connected to master) and use enable pin as a GPIO.

Mark

Mark,

Just to be clear, you desire to have the following signals supported for SPI communications from the SPI slave perspective:

SPICLK
SPISOMI
SPISIMO

Brandon,

You are correct.

SPICLK
SPISOMI
SPISIMO

Mark

Thank you.  As I mentioned, the SPI 3-wire mode of operation uses SPICLK, SPISTE and SPISIMO.

Therefore, you will not be able to recapture SPISTE as a GPIO.

What are you connecting the GPIO to?

It would be possible to use the pin as GPIO and manually toggle it in SW when needed by the SPI.  This would depend on your system configuration though.