In the P2020 QorIQ Integrated Processor Reference Manual, Rev. 2, 12/2012, paragraphs for registers GUTS_SRDSCR0 and GUTS_SRDSCR1 list SerDes Tx equalization settings. But, I'm having a hard time finding info about how the equalization operates. This is for a PCIe application, with a requirement to compensate for channel loss.
* Is it pre-emphasis, where the initial amplitude is increased above the final level set in SRDSCR5[SDTXL0..1] and SRDSCR6[SDTXL2..3]?
* Or is it de-emphasis, where the final amplitude is decreased below the initial level set in SRDSCR5[SDTXL0..1] and SRDSCR6[SDTXL2..3]?
* Or, something else?
* And, for how long does the pre / de-emphasis occur?
The only mention of emphasis or equalization I could find is in the P2020 QorIQ Integrated Processor Hardware Specifications, Rev. 2 manual, Para. 2.20.2 Equalization. But that's in the sRIO section, and is just a general discussion with no specifics relating to QorIQ devices.
* Is there an option to apply receiver equalization?
* Register GUTS_SRDSCR4 controls idle detection for lanes 2 & 3. Is there also a register for lanes 0 & 1?
(curiously, there is no mention of GUTS_SRDSCR3 in the manual, which may or may not be for those lanes)
Thanks for your help.
P2020 QorIQ Integrated Processor Reference Manual, Rev. 2, 12/2012