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authorJoel Sherrill <joel.sherrill@OARcorp.com>2002-07-31 00:16:04 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>2002-07-31 00:16:04 +0000
commit52c5689ecd46a4601aea1104c1c860f8ca48ec05 (patch)
tree52850dfcb53e2cf9657368ed073de75b1de1f184 /doc/supplements/mips/timeBSP.t
parent2002-07-30 Joel Sherrill <joel@OARcorp.com> (diff)
downloadrtems-52c5689ecd46a4601aea1104c1c860f8ca48ec05.tar.bz2
2002-07-30 Joel Sherrill <joel@OARcorp.com>
* .cvsignore: Corrected some errors. * intr_NOTIMES.t, timeBSP.t: Replaced XXX's with real info.
Diffstat (limited to '')
-rw-r--r--doc/supplements/mips/timeBSP.t20
1 files changed, 12 insertions, 8 deletions
diff --git a/doc/supplements/mips/timeBSP.t b/doc/supplements/mips/timeBSP.t
index 63877b8de3..a00259ec94 100644
--- a/doc/supplements/mips/timeBSP.t
+++ b/doc/supplements/mips/timeBSP.t
@@ -15,19 +15,20 @@
@section Introduction
-The timing data for the XXX version of RTEMS is
+The timing data for the MIPS version of RTEMS is
provided along with the target dependent aspects concerning the
gathering of the timing data. The hardware platform used to
gather the times is described to give the reader a better
understanding of each directive time provided. Also, provided
is a description of the interrupt latency and the context switch
-times as they pertain to the XXX version of RTEMS.
+times as they pertain to the MIPS version of RTEMS.
@section Hardware Platform
All times reported except for the maximum period
interrupts are disabled by RTEMS were measured using a Motorola
-BSP_FOR_TIMES CPU board. The BSP_FOR_TIMES is a 20Mhz board with one wait
+BSP_FOR_TIMES CPU board. The BSP_FOR_TIMES is a RTEMS_MAXIMUM_DISABLE_PERIOD_MHZ
+Mhz board with one wait
state dynamic memory and a XXX numeric coprocessor. The
Zilog 8036 countdown timer on this board was used to measure
elapsed time with a one-half microsecond resolution. All
@@ -41,7 +42,8 @@ disabled. The worst case times of the XXX microprocessor
were used for each instruction. Zero wait state memory was
assumed. The total CPU cycles executed with interrupts
disabled, including the instructions to disable and enable
-interrupts, was divided by 20 to simulate a 20Mhz XXX. It
+interrupts, was divided by 20 to simulate a RTEMS_MAXIMUM_DISABLE_PERIOD_MHZ
+Mhz processor. It
should be noted that the worst case instruction times for the
XXX assume that the internal cache is disabled and that no
instructions overlap.
@@ -58,14 +60,16 @@ total of RTEMS_INTR_ENTRY_RETURNS_TO_PREEMPTING_TASK
microseconds. These combine to yield a worst case
interrupt latency of less than
RTEMS_MAXIMUM_DISABLE_PERIOD + RTEMS_INTR_ENTRY_RETURNS_TO_PREEMPTING_TASK
-microseconds at 20Mhz. [NOTE: The maximum period with interrupts
+microseconds at RTEMS_MAXIMUM_DISABLE_PERIOD_MHZ
+Mhz. [NOTE: The maximum period with interrupts
disabled was last determined for Release
RTEMS_RELEASE_FOR_MAXIMUM_DISABLE_PERIOD.]
It should be noted again that the maximum period with
interrupts disabled within RTEMS is hand-timed and based upon
worst case (i.e. CPU cache disabled and no instruction overlap)
-times for a 20Mhz XXX. The interrupt vector and entry
+times for a RTEMS_MAXIMUM_DISABLE_PERIOD_MHZ
+Mhz processor. The interrupt vector and entry
overhead time was generated on an BSP_FOR_TIMES benchmark platform
using the Multiprocessing Communications registers to generate
as the interrupt source.
@@ -93,8 +97,8 @@ is dispatched, RTEMS does not need to save the current state of
the numeric coprocessor.
The exact amount of time required to save and restore
-floating point context is dependent on whether an XXX or
-XXX is being used as well as the state of the numeric
+floating point context is dependent which FPU is being
+used as well as the state of the numeric
coprocessor. These numeric coprocessors define three operating
states: initialized, idle, and busy. RTEMS places the
coprocessor in the initialized state when a task is started or