3.15.4 MAC Syntax

The syntax of the MAC class of instructions can have several formats, which depend on the instruction type and the operation it is performing with respect to prefetches and Accumulator Write-Back. All MAC class instructions must specify a target accumulator along with two multiplicands, as shown in Base MAC Syntax.

If an Accumulator Write-Back is used in the instruction, it is specified last. By definition, the accumulator not used in the mathematical operation is stored, so the Write-Back accumulator is not specified in the instruction. Legal forms of Accumulator Write-Back (WB) are shown in MAC Accumulator WB Syntax.