lambert_yu
Contributor
6 months agoHow could I understand “IOPLL could drive the lvds tx transmitter in adjacent bank"
Hi, In the "arria 10 Core Fabric and General purpose I/O handbook ": There 's one sentence "For differential transmitters, the PLL can drive the differential transmitter channels in its own I...
- 6 months ago
Hi,
that sounds plausible:problem is that tx_outclock is generated differently in single-bank and "wide" SERDES. SERDES IP editor doesn't know about final implementation, thus it accpects tx_outclock phaseshifts that are only applicable in single bank design.
A separate pair of PLL outputs drives tx_outclock SERDES channel through dedicated "phase_shifted_tx_outclock_serdes.outclock_tree". In wide SERDES topology, the phase shifted outclock is apparently not available or not used for some reason. You can only implement phase shift values that are aligned with regular bit clock, e.g. 180° for frequency factor 2.
SERDES IP editor should issue a warning about possible phase shift implementation issues.