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GR716-DS-UM, May 2019, Version 1.29
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GR716
16.6.4 ASR22-23 - Up-counter
The ancillary state registers 22 and 23 (%asr22-23) contain an internal up-counter that can be read by
software without causing any access on the on-chip AMBA bus. The number of available bits in the
counter is 32 bits and is the same as the number of counter bits in the DSU time tag counter. %ASR23
contains the least significant part of the counter value and %ASR22 contains the most significant part.
The time tag value accessible in these registers is the same time tag value used for the system’s trace
buffers and for all processors connected to the same debug support unit. The time tag counter will
increment when any of the trace buffers is enabled, or when the time tag counter is forced to be
enabled via the DSU register interface, or when any processor has its %ASR22 Disable Up-counter
(DUCNT) field set to zero.
The up-counter value will increment even if all processors have entered power-down mode.
Table 124.
LEON3 up-counter MSbs (%ASR22)
31
30
0
DUCNT
Not Used
31
Disable Up-counter (DUCNT) - Disable upcounter. When set to ‘1’ the up-counter may be disabled.
When cleared, the counter will increment each processor clock cycle. Default (reset) value is ‘1’.
30:0
Reserved and not used
Table 125.
LEON3 up-counter LSbs (%ASR23)
31
0
UPCNT(31:0)
31:0
Counter value (UPCNT(31:0)) - Least significant bits of internal up-counter. Read-only.