Timestamp Counter

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Allwinner SoCs contain a timestamp counter that backs the ARM architectural timer. It provides two MMIO separate regions, one for control and one for status, so the control registers can be protected as secure-only.

Note that this hardware block appears to be unrelated to the TSGEN hardware, which looks to be part of the CoreSight debug system.

Registers

Status Register Layout

This block is called TIMESTAMP_STA or CNT_R in the memory map.

Register Offset
CNT_LOW_REG 0x00
CNT_HI_REG 0x04

Control Register Layout

This block is called TIMESTAMP_CTRL or CNT_C in the memory map.

Register Offset
TSTAMP_CTRL_REG 0x00
CNT_LOW_REG 0x08
CNT_HI_REG 0x0c
CNT_FREQID_REG 0x20

CNT_FREQID_REG is also called Cluster0CtrlReg1 in the BSP.

Register Descriptions

See the A83T user manual.