| 摘要 |
A system and method for eliminating the critical path of a processor-based system by sending a signal to transition memory and/or I/O control units to a READ/WRITE state prior to the end of the complete instruction decode. If the decoding phase of the opcode of the instruction reveals that a read-write step is to be carried out wherein memory or an I/O device must be accessed, the processor immediately sends a read-write request to the memory control unit and the I/O control unit prior to decoding the balance of the instruction. Once the balance of the instruction has been decoded and the access location is determined to be in either memory or an I/O device, a cancellation process takes place. In this cancellation process, if the access location is in memory, the I/O unit transitions from the read-write state to an idle state. If, however, the access destination is determined to be an I/O device, the memory control unit transitions from the read-write state to the idle state. |
