Implementing the M Extension: Multiply/Divide Units and Divide-by-Zero
Part 19 of the RISC-V series. I implemented the M extension's multiplier and divider as bit-exact Python models. A single 33-bit multiplier handles all three mulh variants, with zero mismatches across 300,000 pairs and 648 QEMU results, and I found a trap when dividing a negative number by zero (5,039 mismatches).
Sunhong'sSystem Blog
RISC-V