| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the programmable controller which can execute at a high speed instruction words having extension instructions for expanding a data area and indirectly specifying addresses and is advantageous in cost. SOLUTION: In an IF state (stage), an instruction is read out and interpreted in an ID state (stage) and when it is an extension instruction, a return to the IF state (stage) is made to read a following instruction; and the contents of both the extension instruction and following instruction are interpreted together and the instructions begin to be processed (EX1...). When the read instruction is not the extension instruction (Expand), but a normal instruction, an instruction executing process such as data reading and writing, and an arithmetic process is performed according to the instruction interpretation(decoding) result.</p> |
