To add the imultn instruction

[djipi]

Signed Integer Multiply, no Write-Back

Like IMULT, but the result is not written back to the destination register. Intended to be used as the first of a multiply/accumulate group, as there are potential speed advantages in not writing back the result.

Code/Case : 18

Flags
Z – set if the result is zero
N – set if the result is negative
C – not defined

Register Usage
Cycle 1: Source and Destination register read