SPI operation

scanlon · ‎2005-06-03

Posted on June 03, 2005 at 15:24

SPI operation

scanlon · ‎2005-06-03

Posted on June 03, 2005 at 13:47

Hi Everyone.

We are about to switch to STR71 product and I would need a bit of info on the SPI ports. I need to send and receive 32bit words into the STR711 as a SPI slave. Is this possible with the BSPI module? I want to load a 32bit word into the SPI with one long //ss cycle. From what I read, it *looks* like if I clock 32bits into the SPI port, the data will automatically be placed into the next 4 bytes of the buffer.

Does anyone have any thoughts or experience with this? Or maybe details of the specific SPI core that is used?

Thanks in advance,

Ian

scanlon · ‎2005-06-03

Posted on June 03, 2005 at 15:24

Hi RISC,

Thank you for response.

When the spi is slave mode, is a //ss edge required to start and stop transmission?

I don't think I understand the operation of the buffer feature. If I have 4 bytes(to send) in the SPI buffer, what are the requirements to clock that data out? Is a //ss signal required to frame the data into 8 or 16 bits? What I want is to use the //ss signal as a 'gate' to shift 32 bits into 4 bytes in the buffer.

Thanks again