| 摘要 |
PURPOSE:To attain the write of 9-bit surely and easily, by forming a parity bit based on an n-bit data stored in an RAM and writing an (n+1)-bit data to a PROM to use a writer of 8-bit or the like. CONSTITUTION:A data in 8-bit or the like via an I/O buffer 2 is written in an RAM3. A parity generator 5 forms a parity bit in response to the command of odd/even parity via a control section 1 and a register 4 based on the content of the RAM3. This parity bit is written in a PROM as a 9-bit data together with 8-bit information from the RAM3 via an OR circuit 6. Thus, the write of 9-bit(8-bit+1-bit) is attained easily and surely, by using the writer of 8-bit constitution or the like. |
