Kit-059 as SPIM

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lma
Level 3
Level 3
50 sign-ins 10 replies posted 5 questions asked

i am using a Kit-059 as an SPIM to write 256 bits to a cross-point switch that uses a serial data stream interface (data and clock). the cross-point switch does not (specifically) use SPI, so there is no chip select (ss).
the cross-point switch is an analog devices AD75019
i have been examining the SPI signals with an oscilloscope.

i have attached the current state of said project. the immediate goal is to get some output from the processor.
the next goal would be to get more data transferred, so ultimately get all 256 bits transferred.

there have been various incarnations over the last few days, none with any output at xp_data, nor has xp_ss ever gone low.

a variant using three wires - bidirectional data lines instead of miso/mosi data lines also did not work

An attempt to transmit a few bytes, as done in SPIM Example Project 1.10 also failed.

clearly, i am missing something (many things??)

so, a few specific questions:

1) since my slave component (AD75019) does not use the chip select (ss), but i need it connected, what do i connect it to? or is it sufficient to take it to a pin, so the requirement that it be connected appears to be satisfied? 

2) what is missing in the configuration files?

3) what is missing in the main program to tell the processor what to transmit and when?

4) is there a better example?

 

thank you

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pacr_284376
Level 5
Level 5
100 replies posted 10 solutions authored 50 sign-ins

Did you connect and pulse the PCLK ?

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lma
Level 3
Level 3
50 sign-ins 10 replies posted 5 questions asked

pclk is connected and pulsed

i have bypassed the issue by bit banging the data, the clock , and the parallel load.

thank you

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