SBAS745B December 2015 – January 2023 ADS54J66
PRODUCTION DATA
The link layer contains the scrambler and the 8b/10b encoding of any data passed on from the transport layer. Additionally, the link layer also controls the initial lane alignment sequence that can be manually restarted. The link layer test patterns are intended for testing the quality of the link (jitter testing and so forth). The test patterns do not pass through the 8b/10b encoder and contain the options shown in Table 8-6.
BIT | NAME | DEFAULT | DESCRIPTION |
---|---|---|---|
7-5 | LINK LAYER TESTMODE | 000 | These bits generate the pattern according to clause 5.3.3.8.2 of the JESD204B document. 000 = Normal ADC data 001 = D21.5 (high-frequency jitter pattern) 010 = K28.5 (mixed-frequency jitter pattern) 011 = Repeat initial lane alignment (generates a K28.5 character and repeats lane alignment sequences continuously) 100 = 12-octet RPAT jitter pattern |
Furthermore, a 215 PRBS can be enabled by setting up a custom test pattern (AAAA) in the ADC section and running that through the 8b/10b encoder with scrambling enabled.