If There Are Random Problems - Agilent Technologies E5900B User Manual

Chapter 12: Troubleshooting the Emulation Probe
Problems with the Emulation Probe

If there are random problems

Occasionally development systems for the PowerPC using the Agilent
emulation probe can experience erratic behavior, or random target connection
and operation errors or failures. Two major causes for these problems are:
• Crosstalk between the JTAG signals on the cable between the emulation
probe and the target.
• Noise from external fields being coupled into the target connection cable.
Major external fields that can affect this connection include the startup
and shutdown of nearby fluorescent lamps and CRTs. Universal motors in
appliances such as vacuum cleaners and floor buffers can generate
significant field impluses.
The following are two potential solutions to the problems mentioned above.
1. Reduce the TCK clock rate. A reduction from 32 MHz to 10 MHz
(cf speed = 10 M) can cause up to a 50% reduction in the crosstalk. The
most significant side effect is a reduction in download rate. If the increase
in download times cannot be tolerated the TCK rate can be increased for
the duration of the download time, then reduced to gain increased
reliability while debugging.
2. Prove an additional ground path between the emulation probe and the
target system. The SMB connectors on the front of the emulation probe
provide a solid ground connection.
If the particular failure you see is not listed below, contact Agilent Technologies
for assistance.
Test 1: Powerup PV Results
Failure of this test indicates a hardware problem with the emulation probe.
Contact Agilent Technologies for assistance.
Test 2: Emulation Module Port Feedback Test
Failure of this test indicates a hardware problem with the emulation probe.
Contact Agilent Technologies for assistance.
This test exercises the hardware which drives the connection to the emulation
180 Agilent Technologies Emulation for the PowerPC 400/600/700