| 摘要 |
<p>PURPOSE:To easily change a program by storing a fixed subroutine in a mask ROM and storing a main routine in a programmable memory. CONSTITUTION:Many highly versatile subroutines 312 and a main routine writing program 32 are stored in the mask ROM 3 and a CPU executes the program 32 at first. In the program 32, a main routine writing command is received from an I/O terminal, and if the command is not received, the main routine 52 is executed. When the command is received, a main routine writing mode is set up and a program to be received from the I/O terminal is written in the programmable memory 5 to end the program 32. Consequently, the program can easily be changed without changing the contents of the mask ROM 3.</p> |
