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NEC Network Controller uPD98502 User Manual

Page 593

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APPENDIX B V

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4120A COPROCESSOR 0 HAZARDS

Preliminary User’s Manual S15543EJ1V0UM

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(10) Instruction Fetch

Source:

The confirmation of the operating mode and TLB necessary for instruction fetch.

Examples 1.

When changing the operating mode from User to Kernel and fetching instructions after the

KSU, EXL, and ERL bits of the Status register are modified.

2.

When fetching instructions using the modified TLB entry after TLB modification.

(11) Instruction Fetch Exception

Destination:

The completion of writing to registers containing information related to the exception when an

exception occurs on instruction fetch.

(12) Interrupts

Source:

The confirmation of registers judging the condition of occurrence of interrupt when an

interrupt factor is detected.

(13) Loads/Sores

Source:

The confirmation of the operating mode related to the address generation of Load/Store

instructions, TLB entries, the cache mode set in the K0 bit of the Config register, and the

registers setting the condition of occurrence of a Watch exception.

Example

When Loads/Stores are executed in the kernel field after changing the mode from User to

Kernel.

(14) Load/Store Exception

Destination:

The completion of writing to registers containing information related to the exception when an

exception occurs on load or store operation.

(15) TLB Shutdown

Destination:

The completion of writing to the TS bit of the Status register when a TLB shutdown occurs.