Novena DVT to PVT ECO List
Contents
Novena DVT to PVT changes
This is a list of all the changes applied to the board from DVT1 to PVT1 release. If it's not on this list, it didn't happen.
Each change has the format of issue summary/resolution, and specific change
ECO1: Fix Gig-E termination
KSZ9021RN refclk output pull-up drive is weak. Terminate with a 300-ohm pull-up, instead of the proposed AC termination network.
| DVT | PVT | Notes |
|---|---|---|
| R20S 49.9, 1% / REC1005N | DNP | Gigabit ethernet |
| C16S 2200pF, X7R, 50V, 10% / CAPC1005N | DNP | Gigabit ethernet |
| added | 300, 1% / RES1005N | Gigabit ethernet |
ECO2: Remove FPGA clock termination
Use internal FPGA differential termination for clock. Electrically superior to discrete solution.
| DVT | PVT | Notes |
|---|---|---|
| R57B 100, 1% / REC1005N | DNP | FPGA |
ECO3: Clarify D14D orientation
Added fab note on bottom silkscreen layer (outside PCB but inside assy dwg) to indicate that D14D is a side-firing LED. Fab was orienting LED accidentally as vertically firing LED.
ECO4: Add clock margin to Gbit ethernet
RGMII spec assumes an extra 10 inch delay added to the clock wire versus data wire, required to be implemented on the PCB. This is software-compensated by tweaking PHY parameters in the Micrel PHY, but we add these delay line options just in case that option turns out to be unworkable.
TXC line gets 5" added by default in this configuration because it's impossible to measure if the TXC line is adequately delayed and out of paranoia we split the difference.
| DVT | PVT | Notes |
|---|---|---|
| Added | R24G 0 ohm / RES1005N | RX clock path (0 inch option) |
| Added | R22G 0 ohm (DNP) | Rx clock path (5 inch option) |
| Added | R23G 0 ohm (DNP) | Rx clock path (5 inch option) |
| Added | R30G 0 ohm (DNP) / RES1005N | TX clock path (0 inch option) |
| Added | R28G 0 ohm | Tx clock path (5 inch option) |
| Added | R29G 0 ohm | Tx clock path (5 inch option) |
| Added | R27G 0 ohm | Tx clock path (5 inch option) |
| Added | R25G 0 ohm (DNP) | Tx clock path (10 inch option) |
| Added | R26G 0 ohm (DNP) | Tx clock path (10 inch option) |
In addition to these components, a trace is run through the PCB adding these delays.
