| 摘要 |
PURPOSE:To facilitate an easy memory access via the program even for the control unit which has no stack control order, by actuating the part of the memory address by means of the stack function. CONSTITUTION:When the address information shows the stack flag, stack control circuit 122 adds ''1'' to stack pointer 123 in case the command of control line 130 is for writing. And then gate 124 is closed with gate 125 opened each, and the contents of pointer 123 is sent to the address line 111 in the form of the address information. And the data of data line 140 is sent to memory 101 in synchronization with the address sent to line 111. If the command of line 130 is for reading, circuit 122 closes gate 124 and opens gate 125 each to send the contents of pointer 123 to line 111. Then the contents of the corresponding address of memory 101 is read out and then sent to control unit 100 through data line 150, and then ''1'' is subtracted from pointer 123. As a result, the memory access via the program can be facilitated. |
