| 摘要 |
<p>PURPOSE:To confirm the function of a chip without retrial by providing a ROM output control circuit consisting of a first register, a comparator and a second register respectively for ROM code correction, further of a multiplexer, etc. CONSTITUTION:In a first register 6, an address, where the error of a ROM code has been discovered beforehand, is written, a comparator 4 compares the output of the register 6 with the contents of a program counter 1, when the both values coincide, the comparator 4 makes a coincidence signal 103 active. Further an output 102 of a second register 5 is the selective signal of a multiplexer 3, normally the output of a storage area is produced as it is, when the coincidence signal from the comparator 4 is made active, the output of the storage area 3 is altered based on information written in the second register 5 beforehand. Thus by suitably selecting the set value of the register 5, the error of the output of a storage area 2 can be properly corrected.</p> |
