| 摘要 |
PURPOSE:To confirm a privilege at a high speed with a single cycle operation without using a supervisory call nor interruption, by using a gate waiting instruction. CONSTITUTION:An instruction unit 20 stores a lower privilege routine requesting a procedure call in a higher privilege service routine. Then the unit 20 gives an access to a TLB30 via a virtual address bus 35 to seek a gate waiting instruction and then seeks a higher privilege routine to transfer the gate waiting instruction to the unit 20, an execution unit 60 and then a physical target register 70 in a register file 80 respectively from a physical memory 40 via an instruction bus 50. Then an address to be reset from the higher privilege service routine is stored in the register 70 from the unit 20 via a result bus 85. The TBL30 confirms the access right of a call instruction. If this access right is rejected, the execution of the gate waiting instruction is discontinued. |
