Silicon Devices - Others

[kcenriquez123]

I am currently using a single XC17S200A OTP PROM to configure two Spartan-II FPGAs in Master/Slave Serial Mode.

I want to use a XC18V00 Series PROM instead of the OTP PROM. The product specification for the XC18V00 series provides a schematic for the Master/Slave Serial Mode that uses two cascaded PROMs.

Is this the only way to configure the FPGA chain, or is it possible to use a single XC18V02 PROM to configure both devices, similarly to how I am using the XC17S200?

Thanks in advance

[gszakacs · Accepted solution]

The cascaded PROM diagram is just intended to show how to use more than one.  You can use

a single PROM if the designs fit into it.  Just out of curiosity, why are you looking at 18V02 parts

rather than the newer, cheaper XCFxx series like XCF02S?  Unless the 18V02 drops in without

a re-spin to the board layout, the XCF02S is probably a better choice.

-- Gabor

[kcenriquez123]

Thanks. The choice to use a 18V00 series PROM has to do more with packaging types. I have some PC20 and PC44 sockets on hand, and having the capability to swap the PROM on the board is a nice feature in this case. I will, however, take a closer look at the XCFxx series for future projects. Thanks for the recommendation. 

[gszakacs]

Well, for future projects, you're probably better off replacing the Spartan II with a newer

series (Spartan II is already end-of-life) which supports "Master SPI Mode" configuration.

These parts allow you to use very inexpensive commodity SPI flash.

-- Gabor