A Resource Limitation (cont)
Could use four LPM_RAM_DQs configured as 4x9.
However, a RAM_DQ uses an Embedded Array Block (EAB). Only 6 EABs on the the Flex 10K20.
An EAB can be configured as 256 x8, 512 x 4, 1024 x 2, or 2048 x 1. Each 4x9 RAM would take two EABs, would need 8 EABs total! Not enough!
- One solution would be to use three 4x9 RAM_DQs, then make up another “psuedo” RAM_DQ using registers.
- Could store all coefficients in registers, but may run short of gates when implementing the maximum initiation rate solution.