-----Original Message----- From: Corey, Rick Sent: Monday, November 17, 2003 3:27 PM To: 'TA1T' Subject: RE: do Ineed to use a timer if using the SPI as a slave? Hi I don't do the 56827, but if that is a SPI peripheral like the 803-807 peripheral, you never need to set a timer or SCLK when you are the Slave. The Master does all of that. Make sure the revision level on your chip is recent enough that it has working SPI silicon! On the 803, it was only relatively recently that they got MISO putting out non-corrupt data (rev E??) Some eval boards have surprisingly old silicon. By all means put a scope on /SS and make sure it does what you expect - what you set CPHA to require. I only had luck with CPHA=0 (meaning TOGGLE BETWEEN EVERY WORD). We have a consultant who says he got an 807 working with CPHA=1, but I never did. At least make sure that the Master and Slave SPI setups agree on CPHA and CPOL and word length, and bit order, etc etc etc. Are you sure you have /SS connected to both sides without an inverter? On the scope, is MISO flat, or garbagy? Rick Corey -----Original Message----- From: TA1T [mailto:] Sent: Monday, November 17, 2003 3:01 PM To: Subject: do Ineed to use a timer if using the SPI as a slave? I am using the SPI module on the dsp56f827 as a slave. It reads data on the MOSI but doesnt send anything back to the master on the MISO.Do i need to use a quad timer at all. if so WHY,and what frequency should i set the timer to?