There are 4 DSPs (ADSP-TS201SABP-060) on the board ,they communicate with link port in 4 bit data mode and the baud rate is set up 480Mbps. We found that some of the link ports`s communication are error below 0°C. The correct data should be 0x12345678 0x12345679, but the receiver is always read 0x34567800 0x34567912 . We think that the Link Ports [3–0] Data and the the Link Ports Clock are not synchronous. the link port receives clk before data one clk cycle .
We tried to add external 100ohm differential termination resistors and decreased the clock but it was always error .The PCB is according to Link Port LVDS PCB Guidelines .
Our question is why it is correct in nomal temperature and high temperature(from 18°C to 55°C),but mistake below 0°C. And how can we deal