ice40_dsp - iCE40: map multipliers#
- yosys> help ice40_dsp#
ice40_dsp [options] [selection]
Map multipliers ($mul/SB_MAC16) and multiply-accumulate ($mul/SB_MAC16 + $add) cells into iCE40 DSP resources. Currently, only the 16x16 multiply mode is supported and not the 2 x 8x8 mode. Pack input registers (A, B, {C,D}; with optional hold), pipeline registers ({F,J,K,G}, H), output registers (O -- full 32-bits or lower 16-bits only; with optional hold), and post-adder into into the SB_MAC16 resource. Multiply-accumulate operations using the post-adder with feedback on the {C,D} input will be folded into the DSP. In this scenario only, resetting the the accumulator to an arbitrary value can be inferred to use the {C,D} input.