PPT Slide

LDH .D *MemA,A

LDH .D *MemX,X

MPY .M A, X, A*X

ADD .L A*X, Y, Y

STH .D Y,*MemY

Data Memory

.M

.L

A

X

A*X

Y

Sixteen32-bitRegisters

Register File

.D

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Now let’s go back and to our code example and put the functional units by the instructions that are performing the instruction. LDH is done by the .D unit, multiply uses the .M unit, and add uses the .L unit.

From a programming point of view, its easy to see that for more complicated code it would quickly become difficult to keep track of assigning all the functional units to the instructions. In reality, the programmer doesn't have to worry about this task at all. The development tools will automatically do it for them. But, for the sake of this example, to illustrate the functional units and their associated instructions, we will include this coding step.