#619 closed enhancement (fixed)

account for latency when updating decrementer/system clock

Reported by: strauman Owned by: Joel Sherrill
Priority: lowest Milestone: 2
Component: bsps Version: 4.6
Severity: minor Keywords:
Cc: bugs@… Blocked By:
Blocking:

Description

The PPC decrementer must be reloaded on each clock tick.
Currently, this is done by just reloading a fixed value.
The attached patch takes into account the time that elapsed
since the decrementer crossed zero in order to adjust the
value to be re-loaded. Without the patch, the effective system clock cycle is increased by the exception handler latency.

Release:
RTEMS-4.6

Environment:
powerpc/mpc6xx/clock

Attachments (1)

ppc_decrementer_clock_update.diff (2.5 KB) - added by strauman on 12/03/06 at 13:31:12.
ppc_decrementer_clock_update.diff

Download all attachments as: .zip

Change History (2)

comment:1 Changed on 05/22/04 at 14:15:21 by Joel Sherrill

Status: assignedclosed

State-Changed-From-To: open->closed
State-Changed-Why: Patch applied to branch and trunk.

Changed on 12/03/06 at 13:31:12 by strauman

ppc_decrementer_clock_update.diff

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