| 摘要 |
<p>PURPOSE:To read the storage content of a ROM from a few input/output terminals even if the bit width of the storage content of the ROM is increased by incorporating an integrated circuit with 1-bit output ROM in a microcomputer. CONSTITUTION:An address counter 1 and a PROM 2 are arranged on one chip to constitute the integrated circuit 6 with 1-bit PROM. A microprocessor 5 fetches one bit of data of the PROM 2 and outputs a pulse incrementing the content of the address counter 1, fetches one bit of data of the PROM 2 again, applies packing it with the pre-fetch data and increments the content of the address counter 1. The operation above is repeated and when the width of the packed data is equal to the data width of the RAM 4, the microprocessor 5 loads the packed data to the RAM 4. Thus, the number of input/output terminals with the microprocessor 5 is decreased to only three.</p> |
