The OSDTRTX_EL1 characteristics are:
Used for save/restore of DBGDTRTX_EL0. It is a component of the Debug Communications Channel.
This register is part of the Debug registers functional group.
AArch64 System register OSDTRTX_EL1 is architecturally mapped to AArch32 System register DBGDTRTXext.
OSDTRTX_EL1 is a 32-bit register.
The OSDTRTX_EL1 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 |
Return DTRTX without side-effect |
Return DTRTX without side-effect.
Reads of this register return the value in DTRTX and do not change TXfull.
Writes of this register update the value in DTRTX and do not change TXfull.
For the full behavior of the Debug Communications Channel, see 'The Debug Communication Channel and Instruction Transfer Register' in the ARM ARM, chapter H4.
This register can be read using MRS with the following syntax:
MRS <Xt>, <systemreg>
This register can be written using MSR (register) with the following syntax:
MSR <systemreg>, <Xt>
This syntax uses the following encoding in the System instruction encoding space:
<systemreg> | op0 | op1 | CRn | CRm | op2 |
---|---|---|---|---|---|
OSDTRTX_EL1 | 10 | 000 | 0000 | 0011 | 010 |
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.
ARM deprecates reads and writes of OSDTRTX_EL1 when the OS lock is unlocked.
For a description of the prioritization of any generated exceptions, see section D1.13.2 (Synchronous exception prioritization) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile. 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 EL3 is implemented and is using AArch64 :
If MDCR_EL3.TDA==1, accesses to this register from EL1 and EL2 are trapped to EL3.
18/04/2017 17:00
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