Hello,I am having trouble getting my SRAM chip working with my FPGA board. I was wondering if anyone had any tips or extra documentation relating to t...
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Hello,
I am having trouble getting my SRAM chip working with my FPGA board. I was wondering if anyone had any tips or extra documentation relating to these Pipelined SRAM devices. I have attached the datasheet and my Verilog code that interacts with the SRAM IC. When I load the bistream into my FPGA, if I perform a write operation, then a read operation, the data returned from the sram is correct. But if I do multiple writes, then the first piece of data returned is correct, but after that it only returns all 1's. Also when I reset the FPGA and try to read data from the first address(the one I just wrote to), it only returns all 1's. I'll outline my logic for writing to the sram below.
//Clock speed is 100Mhz
Single Write Operation:
1st positive edge of clock:
-Assert CEN
-Assert all CE
-Assert WE
-Assert ADV/LD
-write the correct address onto the address bus
2nd positive edge of clock:
-Deassert OE
-Deassert all CE
-write a dummy address onto the address bus // I don't think this is needed
3rd positive edge of clock:
-write data onto the IO bus // this is the data you want to write into the sram
-Assert all BW pins
Single Read Operation:
1st positive edge of clock:
-Assert CEN
-Assert all CE
-Deassert WE
-Assert ADV/LD
-write the correct address onto the address bus
2nd positive edge of clock:
-Assert OE
-Deassert all CE
-write a dummy address onto the address bus // I don't think this is needed
-Read the data on the IO bus
Currently, I am only trying to go from a deselected state -> read or write -> deselected.
I have no idea what is wrong so I am wondering if I am missing a setup thing or something because I don't think it is writing to the SRAM at all. It should also be noted that I am developing this on a custom FPGA board that I designed myself so there very well could be an issue with how I connected it(See schematic attached). There are a lot of variables at play here so if anyone has any ideas about how my code is wrong, it would be greatly appreciated.
Thank you for your help! 
-Ryan
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Jan 25, 2021
Solved
