JAJSUJ2 May 2024
ADVANCE INFORMATION
Table 9-4 and Table 9-5 describe recommended signal trace length matching requirements. Follow these guidelines to avoid routing long traces over large areas of the PCB:
Figure 9-1 shows an example of the HSSI signal pair routing.
Signals listed in Table 9-4 are specified for data rate operation at up to 3.2Gbps. Minimize the layer changes for these signals. Minimize the number of vias. Avoid sharp turns and layer switching while minimizing the lengths. When layer changes are necessary, place GND vias around the signal vias to provide a signal return path. The distance from one pair of differential signals to another must be at least two times the distance within the pair.
SIGNAL NAME | REFERENCE SIGNAL | ROUTING SPECIFICATION | UNIT |
---|---|---|---|
DMD_HSSI0_N(0...7), DMD_HSSI0_P(0...7) | DMD_HSSI0_CLK_N, DMD_HSSI_CLK_P | ±0.25 | inch |
DMD_HSSI1_N(0...7), DMD_HSSI1_P(0...7) | DMD_HSSI0_CLK_N, DMD_HSSI_CLK_P | ±0.25 | inch |
DMD_HSSI0_CLK_P | DMD_HSSI1_CLK_P | ±0.05 | inch |
Intra-pair P | Intra-pair N | ±0.01 | inch |
SIGNAL NAME | Constraints | Routing Layers |
---|---|---|
LS_CLK_P, LS_CLK_N LS_WDATA_P, LS_WDATA_N LS_RDATA_A | Intra-pair (P to N) Matched to 0.01 inches Signal-to-signal Matched to +/- 0.25 inches | Layers 3, 8 |