AR# 67829


JESD204 - Data Transmission




Once RX register Debug Status bit 3 has asserted, data transmission has started.

Understanding of the JESD204 specification at this point resolves most data issues. 

This article includes tips and tricks for particular devices and set-ups.


Debugging Data Transmission Issues:

K-characters in data

One common occurrence in data transmission is a high amount of K-characters being inserted into the data stream. This is due to alignment character insertion. When repetitive data is seen, alignment characters are inserted to ensure proper DC balancing.

K-characters are inserted to balance the voltage and the protocol understands the purpose of these characters. The other end of the receiver properly views the data.

Control Parameter

With TI ADCs or DACs, it is very important that the correct control parameter is selected. If this is not the case, devices can show very subtle data errors. 

On a waveform, this could show up as subtle jitter at the peaks of a wave.

SYNC Toggling

If a sync signal cycles up and down, the link gets through the CGS and ILAS stages, but most likely a framing parameter is off (parameter mismatch). 

Check for framing parameters on both ends of the link and ensure that they are matched (in particular, F, K, L and M).



Answer Number 问答标题 问题版本 已解决问题的版本
67778 JESD204B - Code Group Sync and Initialization flow N/A N/A
AR# 67829
日期 10/25/2017
状态 Active
Type 综合文章
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