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Using SPORT for SPI port on ADSP-2185?

Started by bitsrflyin December 25, 2003
Has anyone used one of the SPORTs on an ADSP-2185 as an SPI port? I am
trying to interface with an SD card using SPI mode. Really I just need
to read data from the SD card. I have all of the SD specs, but I am
unsure about getting the SPORT to function as an SPI port.

Any ideas would be greatly appreciated.

Andrew Smith
asmith@terrasonde.com (bitsrflyin) wrote in 
news:79af1a54.0312250958.6b7db6d7@posting.google.com:

> Has anyone used one of the SPORTs on an ADSP-2185 as an SPI port? I am > trying to interface with an SD card using SPI mode. Really I just need > to read data from the SD card. I have all of the SD specs, but I am > unsure about getting the SPORT to function as an SPI port. > > Any ideas would be greatly appreciated. > > Andrew Smith >
You can use a SPORT as an SPI port. If the DSP is the SPI master, you can use two NOR gates, such as half a 74VHC02. Here's the recipe: Connect one NOR as an inverter to create /SCLK. This creates a small delay from SCLK so don't skip this step. The input of the first NOR (/SCLK) feeds one input of the 2nd NOR. The other input connects to RFS & TFS (connected together). The output of the 2nd NOR is the SPI_CLK gated clock. DT and DR are MOSI & MISO. Use a FLAG pin if you want an SPI CS. This is the method we use in our DSP-8300 small module (ADSP-2186 based) to communicate with a PIC processor. -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com