C8.7
External Debug Feature Register
The EDDFR characteristics are:
Purpose
Provides top level information about the debug system in AArch64.
Usage constraints
This register is accessible as follows:
Default
RO
Configurations
External register EDDFR is architecturally mapped to the AArch64 ID_AA64DFR0_EL1
register. See
B2.51 AArch64 Debug Feature Register 0, EL1
EDDFR is in the Debug power domain.
Attributes
EDDFR is a 64-bit register.
4 3
8 7
12 11
16 15
20 19
24 23
28 27
0
63
RES
0
RES
0
Debugger
Tracever
PMUver
BRPs
WRPs
CTX_CMPs
RES
0
32 31
Figure C8-6 EDDFR bit assignments
[63:32]
Reserved,
RES0
.
CTX_CMPs, [31:28]
Number of breakpoints that are context-aware, minus 1. These are the highest numbered
breakpoints.
[27:24]
Reserved,
RES0
.
WRPs, [23:20]
Number of watchpoints, minus 1. The value of
0b0000
is reserved.
[19:16]
Reserved,
RES0
.
BRPs, [15:12]
Number of breakpoints, minus 1. The value of
0b0000
is reserved.
PMUVer, [11:8]
Performance Monitors extension version. Indicates whether system register interface to
Performance Monitors extension is implemented. Defined values are:
0x0000
Performance Monitors extension system registers not implemented.
0x0001
Performance Monitors extension system registers implemented, PMUv3.
0x1111
1
IMPLEMENTATION DEFINED
form of performance monitors supported, PMUv3 not
supported.
C8 Memory-mapped debug registers
C8.7 External Debug Feature Register
100236_0100_00_en
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Summary of Contents for Cortex-A35
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