Datasheet

ARMulator Reference
ARM DUI0058D Copyright © 1999-2001 ARM Limited. All rights reserved. 4-19
4.4.4 MRC
This function is called when an
MRC instruction is recognized for a coprocessor. If the
requested coprocessor register does not exist or cannot be written to, the function must
return
ARMul_CP_CANT .
Syntax
unsigned MRC(void *handle, int type, ARMword instr, ARMword *data)
where:
handle is the handle from ARMulif_InstallCoprocessorV5 .
type is the type of the coprocessor access. This can be one of:
ARMul_CP_FIRST indicates that this is the first time the coprocessor
model has been called for this instruction.
ARMul_CP_BUSY indicates that this is a subsequent call, after the first
call was busy-waited.
ARMul_CP_INTERRUPT warns the coprocessor that the ARM is about to
service an interrupt, so the coprocessor must
discard the current instruction. Usually, the
instruction will be retried later, in which case the
type will be reset to ARMul_CP_FIRST.
ARMul_CP_DATA
indicates that valid data is included in *data .
instr is the current opcode.
data is a pointer to the location of the data being transferred from the
coprocessor to the core.
Return
The function must return one of:
•
ARMul_CP_DONE , to indicate that the coprocessor operation is complete, and valid
data has been returned to
*data .
•
ARMul_CP_BUSY , to indicate that the coprocessor is busy
•
ARMul_CP_CANT , to indicate that the instruction is not supported, or the specified
register cannot be accessed.