| 摘要 |
PURPOSE:To control a multi-purpose loop with a short instruction by using a program counter, a program stack and a stack pointer and branching the pop signals to be applied to the stack pointer to supply them to a read instruction input part of the program stack. CONSTITUTION:A microcomputer input control circuit contains a program counter 1, a page register 2, a bank register 3, a program stack 4 and a stack pointer 5. The input signals of a stack pop signal line 11 are branched and supplied to the pointer 5 via an OR gate 18 as well as to the stack 4 via an OR gate 19. While a stack push (down) signal line 12 is connected to the stack 4 and the pointer 5. A stack-up signal line 19 and a stack read signal line 21 are connected to the inputs of gates 18 and 19 respectively. In such a way, it is easy to realize a multi-purpose loop for programming. Furthermore all loop control instructions can be obtained with the shortest instruction length of the microcomputer. |
