Pmods : using for interfacing external ram

[supriyak]

Hi,

I am writing a systemverilog controller for read and write to ft313 chip internal memory.

Kindly help me on whether i can use pmod for the  external interface  which consists of 16 bit bidirectional data, 8bit address bus, chip select, read and write signal. with outputs defined as reg, Do i have to use bram specifically or it is taken care if defined as reg.

 

 

[D@n]

@supriyak,

PMods only have 4 data bits per rank, or at most 8 data bits per PMod.  It'd be kind of hard to hit the requirement you are asking for.  A 16-bit bidirectional data bus with 8 address bits would require a minimum of three PMod's ganged together--and that's even before you get to the control bits.  I don't know of anyone offering such a solution.

That said, 1bit squared has built a HyperRAM PMod that gets some good performance, so it might work for your application.  HyperRAM uses an 8-bit bidirectional DDR data bus, for address and data, together with a number of side channel control wires that look sort of like SPI signals.  You might want to check it out.

Dan

[zygot]

3 hours ago, supriyak said:

I am writing a systemverilog controller for read and write to ft313 chip internal memory

Your chances of using PMODs to implement the 16-bit FT313 interface are zero. There are numerous reasons for this. You might be able to make an FMC mezzanine card to do this if you platform has an FMC connector.

If you are using a soft-processor like MicroBlaze I don't give you favorable odds at implementing the software support that you need for a USB Host, even with the simplification provided by the FT313. Even a ZYNQ platform will be problematic since you will have to go through AXI bus to get to the PS.