SBAS649B June 2021 – June 2022 DAC12DL3200
PRODUCTION DATA
The device provides the ability for the user to provide a repeating 8-sample sequence on the LVDS inputs and verify that the data can be properly received. It also provides debug facilities to help the user determine where the failures are occurring.
The test can be run both stop-on-fail (which allows the user to read the failing data frame to see what bits are failing and at what point in the pattern) or continue-on-fail (which allows the user to get a quick overview of which datalines are having problems).
Individual LVDS banks can be masked allowing the user to capture failures on selected banks.
Start the DEVCLK
Apply power
Assert Reset
De-assert Reset – Fuse ROM load will automatically begin
Configure CH_CFG and DCM_EN according to the desired mode of operation. Only LVDS banks that are used in the selected mode will be tested.
Start LVDS data into the part using the proper strobe period. Note that it is possible to use either the LSB strobe or the dedicated strobe pin. If using the LSB strobe, set SYNCB low (using either the pin or the register bit).
Set DP_EN=1
Synchronize the system
If using LVDS Strobes for alignment:
Set LVDS_STROBE_ALIGN=1
Wait for LVDS_STROBE_DET=1
If using SYSREF for alignment
See SYSREF Windowing to enable and align synchronous SYSREF capturing.
Set SYSREF_ALIGN_EN=1
Wait for SYSREF_DET=1
Set SYSREF_ALIGN_EN=0
Check LVDS_STROBE_DET to ensure all the required LVDS strobes have been detected. Be sure to reset the bits before reading them. (Note that it is still possible to run the IOTEST if some strobes are not working. To do this, ensure that SYSREF is not being used so the FIFO does not corrupt the data. Then continue performing the test. The test will likely fail, but will provide visibility into what is occurring on the strobe line.)
Configure FIFO_DLY (this may be done early but should be complete by here)
Configure the IOTEST data patterns in IOTEST_PAT, and IOTEST_CONT.
Set IOTEST_STRB_LOCK=1 (if desired).
If using an LSB strobe and the pattern tests the LSb in data operation, set LSB_SYNC=0 and sync_n=1.
Set IOTEST_EN=1
Enable Transmission using txenable or TXEN_A/B.
Start the test using IOTEST_TRIG.
If IOTEST_CONT = 0, monitor IOTEST_RUN until the test stops and then inspect the results. If IOTEST_CONT = 1, monitor the faults using IOTEST_SUM or IOTEST_MISS* fields in registers IOTEST_STAT0 - IOTEST_STAT3.