8_BITS_CONTROL_128_BITS

Published:2009/7/6 21:20:00 Author:May | From:SeekIC

Combination of 74154 demultiplexer and 16 NE591 latches permits control of 128 single-bit outputs with standard 8-bit parallel output of microprocessor. Latches are driven from three low-order bits of microprocessor. Next four higher bits drive 74154 which in turn drives chip-enable inputs of NE591s. Eighth bit of microprocessor drives data inputs of all latches and sets addressed bits appropriately.-R. D. Grappel, Control 128 Bits with an 8-BitμC Port, EDN Magazine, Sept. 5, 1978, p 70 and 72.



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