Logic Analyzer Self-Tests

Chapter 8: Theory of Operation

Self-Tests Descriptions

Trigger Arm Test. The Trigger Arm Test verifies that the local arm signal can be received by the master acquisition IC on the acquisition board. The test also verifies the global arm signal can be driven by each acquisition IC on a master board and received by all acquisition ICs on the card. The arm lines are asserted and read at the acquisition ICs to ensure each acquisition IC recognizes the signal.

Passing the Trigger Arm Test implies any acquisition IC can arm the card and that all acquisition ICs can recognize the arm signal.

Clock Paths Test. The Clock Paths Test verifies that the system Master, Slave, and Psync clocks are functional between the acquisition ICs. The module is configured to take a simple measurement. Test data is then created at the comparators and an acquisition taken. The resulting data is then downloaded and compared with known values.

Passing the Clock Paths Test implies that all acquisition IC clock lines can be driven by each acquisition IC and can be received by each acquisition IC in the module. Consequently each acquisition IC can reliably acquire data in response to the acquisition clock signal.

Memory Modes Test. The Memory Modes Test verifies the CPU interface can properly manage the acquisition memory unload in full channel, half-channel, count only, and interleaved modes. Test data is written to acquisition memory. Different unload modes are selected, then the data is read and compared with known values.

Passing the Memory Modes Test implies that the data can be reliably read from acquisition memory in full channel, half-channel, count only, and interleaved mode. This test along with the Memory Test provides complete testing of acquisition memory downloading through the 1394 interface.

Calibration Test. The Calibration Test ensures that each acquisition IC in the module can perform an operational accuracy self-calibration. Various self- calibration routines are initiated. The results of each self-calibration routine are then checked to see if the self-calibration was successful or not.

Passing the Calibration Test implies that the module can reliably perform an operation accuracy self-calibration. Consequently the incoming data path is optimized to reduce channel-to-channel skew so the acquisition ICs can reliably capture the incoming data.

Register Test. The Register Test verifies that the registers of each acquisition IC is operating properly. Test patterns are written to each register on each acquisition IC, read, and compared with know values. The registers are reset, and