Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet
Product codes
AT91SAM9N12-EK
Coprocessor Interface
ARM DDI0198D
Copyright © 2001-2003 ARM Limited. All rights reserved.
8-9
8.5
Privileged instructions
The coprocessor might restrict certain instructions for use in privileged modes only. To
do this, the coprocessor has to track the nCPTRANS output.
do this, the coprocessor has to track the nCPTRANS output.
Figure 8-7 shows how nCPTRANS changes after a mode change.
Figure 8-7 Privileged instructions
Decode
Execute
Memory
CLK
CPINSTR[31:0]
nCPMREQ
nCPTRANS
CPLATECANCEL
CHSDE[1:0]
CHSEX[1:0]
Coprocessor pipeline
Instruction
aborted
Fetch
CPRT
Ignored
LAST
Ignored
Decode
Ignored
Decode
Old mode
New mode
CPPASS