RE: [ECOS] Question About "Clock Hardware Initialization Value"

[Gary Thomas <gthomas@cambridge.redhat.com>]

On 23-Apr-2001 Huang Qiang wrote:
> Hi all:
>    I am configuring the tick time for the ecos. I met with a clock hardware
> initialization value option in the ecos configuration tool. It recommend to
> refer to the hardware reference. Does it mean the target platform or the
> microprocessor's manual? I am currently using the ARM Evaluator7T Board for
> developing. What is this value used to do?

The answer to this depends on the actual hardware platform.  Sometimes the
hardware (registers, timers, etc) used for the tick timer are on the processor
(in the case of the Evaluator), other times it is implemented in separate
logic on the target board.

In your case, look at the E7T documentation on the internal timers to figure
out what the value should be.  You can probably get some idea from seeing the
current value.

Specifically for the Evaluator, the timer is clocked by the system clock, so
the "period" value is simply the system clock divided by the timer rate.  In
the current CDL, these values are calculated, so in order to change them you'll
have to edit the CDL file directly.