| 摘要 |
<p>PROBLEM TO BE SOLVED: To evade the erroneous discrimination of a communication mode due to initialization trouble by performing negotiation before the initialization of peripheral equipment which is high in frequency of use. SOLUTION: Prior to the initialization of the peripheral equipment which is high in frequency of use, the CPU 100 of a personal computer 50 negotiates with the CPU 200 on the side of a printer 150. Namely, the CPU 100 sends various mode requests to the CPU 200 of the printer 150 by following the procedure determined by the IEEE1284 standards and decides the conformity with the IEEE1284 standards according to answer results sent back from the CPU 200. When this negotiation is successful, a reset command is set to initialize the printer 150 and a communication is carried out in nibble mode, ECP mode, etc. If a failure in the negotiation is decided, termination is performed.</p> |
