ARM R4F Computer Hardware User Manual


 
Debug
ARM DDI 0363E Copyright © 2009 ARM Limited. All rights reserved. 11-35
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Table 11-29 shows how the bit values correspond with the Lock Status Register functions.
11.5.5 Device Type Register
The Device Type Register is a read-only register that indicates the type of debug component.
Figure 11-19 shows the bit arrangement of the Device Type Register.
Figure 11-19 Device Type Register format
Table 11-30 shows how the bit values correspond with the Device Type Register functions.
11.5.6 Debug Identification Registers
The Debug Identification Registers are read-only registers that consist of the Peripheral
Identification Registers and the Component Identification Registers. The Peripheral
Identification Registers provide standard information that all CoreSight components require.
Only bits [7:0] of each register are used. The remaining bits Read-As-Zero.
The Component Identification Registers identify the processor as a CoreSight component. Only
bits [7:0] of each register are used, the remaining bits Read-As-Zero. The values in these
registers are fixed.
Table 11-29 Lock Status Register functions
Bits Field Function
[31:3] Reserved Do not modify on writes. On reads, the value returns zero.
[2] 32-bit access Indicates that a 32-bit access is required to write the key to the Lock Access Register.
This bit always reads 0.
[1] Locked bit Locked bit:
0 = Writes are permitted.
1 = Writes are ignored. This is the reset value.
[0] Lock implemented bit Indicates that the OS lock functionality is implemented. This bit always reads 1.
31
31 0
Reserved
4
Sub type Main class
87 3
Table 11-30 Device Type Register functions
Bits Field Function
[31:8] Reserved Do not modify on writes. On reads, the value returns zero.
[7:4] Subtype
0x1
, indicates that the sub-type of the device is processor core.
[3:0] Main class
0x5
, indicates that the main class of the device is debug logic.