Auxiliary Register Arithmetic Unit (ARAU)
3-14
execute phase of the pipeline. For information on the operation of the pipeline,
see Section 5.2 on page 5-7.
In addition to using the auxiliary registers to reference data-memory address-
es, you can use them for other purposes. For example, you can:
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Use the auxiliary registers to support conditional branches, calls, and re-
turns by using the CMPR instruction. This instruction compares the con-
tent of AR0 with the content of the current AR and puts the result in the
test/control flag bit (TC) of status register ST1.
-
Use the auxiliary registers for temporary storage by using the LAR instruc-
tion to load values into the registers and the SAR instruction to store AR
values to data memory.
-
Use the auxiliary registers as software counters, incrementing or decre-
menting them as necessary.