Phase 1 of migrating mlkem_top's large arrays to inferable RAM. ek_mem
and dkp_mem reg arrays are replaced by two sd_bram instances (1R/1W,
registered read). Datapath changes to fit single-port-per-cycle BRAM:
- ST_E writes 1 byte/cycle (was 3): added e_byte sub-counter; ST_E
length ~3x (K=2 KeyGen 21403->22433 cyc, ~5%).
- ST_H ek read is now registered: assemble phase presents the address
one cycle ahead and writes back the byte that arrived (h_wb_* pipe),
h_byte runs 0..136 to flush the final byte. Pad bytes via h_padconst.
- dbg_byte_o/dbg_dk_o read combinationally off the BRAM registered
output (net 1-cycle latency, within the TB's 2-cycle read wait);
region decode for dk readback unchanged.
Add sd_bram.v to the top TB compile list. Verified byte-exact vs NIST
KAT: K=2 c0-4, K=3 c0-2, K=4 c0-2 -> 11/11 PASS, 0 file-not-found.
FallenSigh
5a7d5d6a47