| 摘要 |
PURPOSE:To set a device identification number automatically by counting up a constant number of digits automatically by a register when a processor is powered on and writing the data of the register in a nonvolatile memory. CONSTITUTION:The nonvolatile RAM 3 of a processor which has a keyboard KB 6 and a CPU 1 is backed up by a battery 31 even when the processor is powered off, thereby holding its storage contents. A CPU 1 performs processing automatically by an initial program stored in its ROM 4 when powered on and counts up the constant number of digits by its internal register. The CPU 1 reads the status of a keyboard adapter 61 to judge the keying state of the KB 6 and write the data in the register in the RAM 3 at the 1st input timing. Consequently, an unpredictable device identification number can be set automatically during the manufacture of the processor without performing individual operation. |
