Programmable ROM in ASIC

[kevinj]

Hi,

I'm using Verilog to create an ASIC and then later using Encounter to synthesize the design. In Verilog I use a Block ROM to store some coefficients, however for the ASIC I would like to stream in the coefficients as those values change from one ASIC to the other. I'm thinking about using some sort of SPI interface. Is there a simple way of achieving this? Or how would I go about doing this? I'm targeting this design for UMC 90nm.

Thanks

 

[FvM]

Is there a simple way of achieving this?

I think so.

Connecting all parameter bit registers to a chain would be basically sufficient to load parameters. A second register set to latch the data from shift register would extent the interface to standars SPI and also allow parameter reload during operation.

 

[kevinj]

Thanks for the reply. Is there any way to have the data be stored indefinitely, something along the lines of an internal EEPROM? Or do I need to have an external EEPROM and have the ASIC read in the values to the registers during bootup?

Thanks

 

[FvM]

I wouldn't expect EEPROM cells in an usual ASIC process.