The CNTFRQ characteristics are:
This register is provided so that software can discover the frequency of the system counter. The instance of the register in the CNTCTLBase frame must be programmed with this value as part of system initialization. The value of the register is not interpreted by hardware.
The power domain of CNTFRQ is IMPLEMENTATION DEFINED.
For more information see 'Power and reset domains for the system level implementation of the Generic Timer'.
CNTFRQ is a 32-bit register.
The CNTFRQ 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 |
Clock frequency |
Clock frequency. Indicates the system counter clock frequency, in Hz.
This field resets to an architecturally UNKNOWN value.
CNTFRQ must be implemented as an RW register in the CNTCTLBase frame.
In a system that recognizes two Security states, the instance of the register in the CNTCTLBase frame is only accessible by Secure accesses.
CNTFRQ can be implemented as a RO register in any implemented CNTBaseN frame, and in the corresponding CNTEL0BaseN frame.
'CNTCTLBase status and control fields for the CNTBaseN and CNTEL0BaseN frames' describes the status fields that identify whether a CNTBaseN frame is implemented, and for an implemented frame:
For an implemented CNTBaseN frame:
For an implemented CNTEL0BaseN frame:
Component | Frame | Offset | Instance |
---|---|---|---|
Timer | CNTBaseN | 0x010 | CNTFRQ |
Accesses on this interface are RO.
Component | Frame | Offset | Instance |
---|---|---|---|
Timer | CNTEL0BaseN | 0x010 | CNTFRQ |
Accesses on this interface are RO.
Component | Frame | Offset | Instance |
---|---|---|---|
Timer | CNTCTLBase | 0x000 | CNTFRQ |
Accesses on this interface are RO.
01/07/2020 15:57; 80324f0b9997bede489cc15ad1565345720bcd2a
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