The DBGOSECCR characteristics are:
Provides a mechanism for an operating system to access the contents of EDECCR that are otherwise invisible to software, so it can save/restore the contents of EDECCR over powerdown on behalf of the external debugger.
This register is part of the Debug registers functional group.
There is one instance of this register that is used in both Secure and Non-secure states.
AArch32 System register DBGOSECCR is architecturally mapped to AArch64 System register OSECCR_EL1.
AArch32 System register DBGOSECCR is architecturally mapped to External register EDECCR.
If OSLSR.OSLK == 0 then DBGOSECCR returns an UNKNOWN value on reads and ignores writes.
DBGOSECCR is a 32-bit register.
The DBGOSECCR bit assignments are:
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
EDECCR |
Used for save/restore to EDECCR over powerdown.
Reads or writes to this field are indirect accesses to EDECCR.
This register can be read using MRC with the following syntax:
MRC <syntax>
This register can be written using MCR with the following syntax:
MCR <syntax>
This syntax uses the following encoding in the System instruction encoding space:
<syntax> | opc1 | opc2 | CRn | coproc | CRm |
---|---|---|---|---|---|
p14, 0, <Rt>, c0, c6, 2 | 000 | 010 | 0000 | 1110 | 0110 |
The register is accessible as follows:
Control | Accessibility | |||||
---|---|---|---|---|---|---|
E2H | TGE | NS | EL0 | EL1 | EL2 | EL3 |
x | x | 0 | - | RW | n/a | RW |
x | 0 | 1 | - | RW | RW | RW |
x | 1 | 1 | - | n/a | RW | RW |
This table applies to all instructions that can access this register.
For a description of the prioritization of any generated exceptions, see section G1.11.2 (Exception priority order) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile for exceptions taken to AArch32 state, and section D1.13.2 (Synchronous exception prioritization) for exceptions taken to AArch64 state. Subject to the prioritization rules, the following traps and enables are applicable when accessing this register.
When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 :
If MDCR_EL2.TDA==1, Non-secure accesses to this register from EL1 are trapped to EL2.
When EL2 is implemented and is using AArch32 and SCR_EL3.NS==1 :
If HDCR.TDA==1, Non-secure accesses to this register from EL1 are trapped to Hyp mode.
When EL3 is implemented and is using AArch64 :
If MDCR_EL3.TDA==1, accesses to this register from EL1 and EL2 are trapped to EL3.
28/09/2017 08:24
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