User guide
Embedded Trace Macrocell
ARM DDI 0337I Copyright © 2005-2008, 2010 ARM Limited. All rights reserved. 10-17
ID072410 Non-Confidential
10.3.7 ID Register, ETMIDR
The ETMIDR characteristics are:
Purpose Holds the ETM architecture variant, and defines the programmers model
for the ETM.
Usage constraints There are no usage constraints.
Configurations This register is only available if the processor is configured to use the
ETM.
Attributes See the register summary in Table 10-6 on page 10-9.
Figure 10-6 shows the ETMIDR bit assignments.
Figure 10-6 ETMIDR bit assignments
Table 10-11 shows the ETMIDR bit assignments.
Implementor code
Support for Security Extensions
31 17 16 15 12 8 7 4 3 018 11
ETM architecture
version number
Load PC first
24 23 20 19
Major Minor
Implementation
revision
Processor
family
21
ReservedSupport for 32-bit Thumb instructions
Implements alternative branch packet encoding
Reserved
Table 10-11 ETMIDR bit assignments
Bits Name Function
[31:24] Implementer code These bits identify ARM as the implementer of the processor. The value of these bits is
0b01000001
.
[23:21] - Reserved.
[20] Branch packet encoding The value of this bit is 1, indicating that alternative branch packet encoding is implemented.
[19] Security Extensions
support
The value of this bit is 0, indicating that the ETM behaves as if the processor is in Secure
state at all times.
[18] 32-bit Thumb instruction
tracing
The value of this bit is 1, indicating that a 32-bit Thumb instruction is traced as a single
instruction.
[17] - Reserved.
[16] Load PC first The value of this bit is 0, indicating that data tracing is not supported.
[15:12] Processor family The value of these bits is
0b1111
, indicating that the processor family is not identified in this
register.
[11:8] Major ETM architecture
version
The value of these bits is
0b0010
, indicating major architecture version number 3, ETMv3.
[7:4] Minor ETM architecture
version
The value of these bits is
0b0101
, indicating minor architecture version number 5.
[3:0] Implementation revision The value of these bits is
0b0011
, indicating implementation revision, 3.