UMAC CPU with an option 5D0 and 5D3 (100Mhz CPU) will occasionally watchdog, when I52=9.

       
 

 

Problem:

A memory access timing issue between the UMAC CPU and the on board memory causes the UMAC CPU watchdog to trip.
Symptom:

UMAC CPU watchdog indicator (Red Light on the front of the CPU) will be active, if I52 = 9.
What is I52?

Solution:

1) Upgrade CPU firmware to 1.940 (This firmware has a new I-variable, I37. I37 is a wait state setting parameter.)
How do I change the firmware?
Download Firmware Version 1.940
Turbo software addendum for firmware versions V1.938, V1.939, & V1.940.

2) Enter the following commands into the terminal window.

I37=$2400 ; set 1 wait state to XY memory and P memory.
I52=9
SAVE
$$$