IA2910A

Data Sheet

Microprogram Controller

August 19, 2008

IA211030314-03

http://www.Innovasic.com

Customer Support:

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1-888-824-4184

The register/counter is operated during three microinstructions (8, 9, and 15) as a 12-bit down

counter, with result = zero available as a microinstruction branch test criterion. This provides

efficient iteration of microinstructions. The register/counter is arranged such that if it is preloaded

with a number N and then used as a loop termination counter, the sequence will be executed exactly

N + 1 times. During instruction 15, a three-way branch under combined control of the loop

counter and the condition code is available.

The device provides three-state YOUT outputs. These can be particularly useful in designs

requiring automatic checkout of the processor. The microprogram controller outputs can be forced

into the high-impedance state, and pre-programmed sequences of microinstructions can be executed

via external access to the address lines.