ARM R4 Manuale Utente
Programmer’s Model
ARM DDI 0363E
Copyright © 2009 ARM Limited. All rights reserved.
2-27
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2.9
Acceleration of execution environments
Because the ARMv7-R architecture requires Jazelle
®
software compatibility, three Jazelle
registers are implemented in the processor.
Table 2-7 shows the Jazelle register instruction summary and the response to the instructions.
Note
Because no hardware acceleration is present in the processor, when the
BXJ
instruction is used,
the
BX
instruction is invoked.
Table 2-7 Jazelle register instruction summary
Register
Instruction
Response
Jazelle ID
MRC p14, 7, <Rd>, c0, c0, 0
MCR p14, 7, <Rd>, c0, c0, 0
Read as zero
Ignore writes
Ignore writes
Jazelle main configuration
MRC p14, 7, <Rd>, c2, c0, 0
MCR p14, 7, <Rd>, c2, c0, 0
Read as zero
Ignore writes
Ignore writes
Jazelle OS control
MRC p14, 7, <Rd>, c1, c0, 0
MCR p14, 7, <Rd>, c1, c0, 0
Read as zero
Ignore writes
Ignore writes