SPI Interrrupts

[v_dave]

Hello All,

My project uses the 56F8323 and Codewarrior for the DSC56F00\E. 

I am trying to setup the SPI port to be fully interrupt driven.  Using the PE SPI Bean it seems pretty straight forward.  In fact right now I have an Interrupt drivien transmit routine.  I need to go to the next level to finish my transimission sequence.  I need to know when the shift register is actually done sending the data.  I don't see an Event in the Bean.  I also have reviewed chapter 14 in the Peripheral User Manul and I don't see a flag or an Interrupt that lets you know when the shift register is complete. 

My issue is the particular SPI device I am talking to does not latch the data until the SS pin is raised.  so right now I have to start a timer loop that waits an estimated amount of time for the shift register to be done then raise the SS line manually.

I would like to have an INT (or at least be able to poll a flag) that tells me the shift register is done then raise the SS line.

Any ideas?

[rocco · Accepted solution]

Hi Dave,

Since the SPI transmit and receive are synchronous to each other, one possible approach is to use the SPI's receiver interrupt as an indication that shifting has completed.

[v_dave]

Hello,

Thanks for the quick reposnse. 

After reading your tip I rered the Peripheral User Manual and found in section 14.1.1 a small mention of using the Recieve interrupt as the TX Complete flag. 

This looks like a good solution.

[bob_s]

The receive interrupts works for me with one exception which is at best confusing.  If I send a zero value out the transmit port which is valid for my SPI slave, the receive interrupt on 8323 master does not occur.  Any explanations for this behavior?