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Altera_Forum
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12 years ago

Building an SPI Decoder into Altera

Hello, I am working on a project which requires interfacing between a Microcontroller and an Altera FPGA. I'm using an Arduino UNO and DE0Nano Cyclone IV. The Arduino sends a 64bit word via SPI...
Altera_Forum's avatar
Altera_Forum
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12 years ago

normally the process list should only contains the clock (or an asynchrounous reset) so you could try by changing

process (SPI_Clk, SPI_Data, SPI_Sel, shift_reg64) begin

into

process (SPI_Clk)

and

process (SPI_Sel, shift_reg64)

into

process (SPI_Sel)

but I still wouldn't recommend this because you create two clock domains by doing this (SPI_SEL & SPI_Clk). I think it's much better if you process everything on some clock present in your FPGA (maybe the clock you use to read the outA , outB, ... with ? )