The CNTV_TVAL characteristics are:
Holds the timer value for the virtual timer.
The power domain of CNTV_TVAL is IMPLEMENTATION DEFINED.
On a reset of the reset domain in which an RW instance of this register is implemented, RW fields in the register reset to UNKNOWN values. The register is not affected by a reset of any other reset domain. For more information see 'Power and reset domains for the system level implementation of the Generic Timer' in Chapter I1 of the Arm® Architecture Reference Manual, Armv8, for Armv8-A architecture profile.
CNTV_TVAL is a 32-bit register.
The CNTV_TVAL 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 |
TimerValue |
The TimerValue view of the virtual timer.
On a read of this register:
On a write of this register, CompareValue is set to (CNTVCT + TimerValue), where TimerValue is treated as a signed 32-bit integer.
When CNTV_CTL.ENABLE is 1, the timer condition is met when (CNTVCT - CompareValue) is greater than or equal to zero. This means that TimerValue acts like a 32-bit downcounter timer. When the timer condition is met:
When CNTV_CTL.ENABLE is 0, the timer condition is not met, but CNTVCT continues to count, so the TimerValue view appears to continue to count down.
This field resets to an architecturally UNKNOWN value.
CNTV_TVAL can be implemented in any implemented CNTBaseN frame that has virtual timer capability, and in the corresponding CNTEL0BaseN frame.
'CNTCTLBase status and control fields for the CNTBaseN and CNTEL0BaseN frames' in Chapter I1 of the Arm® Architecture Reference Manual, Armv8, for Armv8-A architecture profile describes the status fields that identify whether a CNTBaseN frame is implemented, and for an implemented frame:
For an implemented CNTBaseN frame that has virtual timer capability:
For an implemented CNTEL0BaseN frame:
Component | Frame | Offset | Instance |
---|---|---|---|
Timer | CNTBaseN | 0x038 | CNTV_TVAL |
Access on this interface is RW.
Component | Frame | Offset | Instance |
---|---|---|---|
Timer | CNTEL0BaseN | 0x038 | CNTV_TVAL |
Access on this interface is RW.
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