Experimental Physics and
Industrial Control System

[email protected] · Mon, 16 Jan 95 13:50:35 -0600

Hmmmm that is 33.3333333333333333333% off the expected speed.  I find
it interesting to note that 33 is 33.33.3333333333333333333% more than
25.  I don't fully understand your entire note.  But I suspect that you
have a 33mHz mvme167 board that has its vxWorks configured for a 25mHz
board.

There is a comment in config/mv167/target.nr:

    SPECIAL CONSIDERATIONS

    The value of the CPU clock speed, e.g., 25 MHz or 33 MHz, needs to
    be written into NVRAM.  NV_CPU_SPEED is defined in config.h as the
    address for this value (0xfffc00fe).  The location (NV_CPU_SPEED + 1)
    is used to validate the contents of NV_CPU_SPEED.  If this location
    contains 0xee then the contents of NV_CPU_SPEED will be used,
    otherwise 25 MHz will be used as the CPU speed.  If this value is
    not set properly, the registers initialized with this value will be
    wrong.

I don't exectly know how to set the value in the NVRAM to to proper
value, but that would be the nice way to fix the problem...  Otherwise
you will have to change the hard-coded clock rate settings in sysLib.c.
Grep for 'cpuSpeed' in sysLib.c to find the line(s) of interest.  (WRS
blew it, the value on the assignment should be #define'd.)

--John

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System