Motorola M68000 User Manual download pdf (Page 204)

Supervisor (Privileged) Instructions

MOTOROLA M68000 FAMILY PROGRAMMER’S REFERENCE MANUAL 6-41

PFLUSHR Invalidate ATC and RPT Entries PFLUSHR

(MC68851)

Operation: If Supervisor State

Then RPT Entry (If Any) Matching Root Pointer Speciﬁed by < ea >

Corresponding Address Translation Cache Entries Are Invalidated

Else TRAP

Assembler

Syntax: PFLUSHR < ea >

Attributes: Unsized

Description: The quad word pointed to by < ea > is regarded as a previously used value of

the CPU root pointer register. The root pointer table entry matching this CPU root

pointer register (if any) is ﬂushed, and all address translation cache entries loaded with

this value of CPU root pointer register (except for those that are globally shared) are

invalidated. If no entry in the root pointer table matches the operand of this instruction,

no action is taken.

If the supervisor root pointer is not in use, the operating system should not issue the

PFLUSHR command to destroy a task identified by the current CPU root pointer reg-

ister. It should wait until the CPU root pointer register has been loaded with the root

pointer identifying the next task until using the PFLUSHR instruction. At any time, exe-

cution of the PFLUSHR instruction for the current CPU root pointer register causes the

current task alias to be corrupted.

Instruction Format:

1514131211109876543210

1111000000

EFFECTIVE ADDRESS

MODE REGISTER

1010000000000000

1 2 ... 199 200 201 202 203 204 205 206 207 208 209 ... 356 357

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Motorola M68000 User Manual Page 204