Novena EVT to DVT changes
Contents
Novena EVT to DVT changes
This is a list of all the changes applied to the board from EVT1A to DVT1 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: Inrush current limit
The RC constant governing the turn-on/turn-off rates of the FET power switches needs tuning. In EVT, most switches are turning on too quickly for them to be effective. Resolution is to increase capacitance and resistance.
EVT | DVT | Notes |
---|---|---|
R38N 330, 1% / REC1005N | R38N 10k, 1% / RESC1005N | P3.3V_DELAYED |
C30N 0.1uF, 6.3V, X5R / CAPC0603N_B | C30N 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | P3.3V_DELAYED |
R29N 330, 1% / REC1005N | R29N 10k, 1% / RESC1005N | P5.0V_DELAYED |
C27N 0.1uF, 6.3V, X5R / CAPC0603N_B | C27N 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | P5.0V_DELAYED |
R11H 330, 1% / REC1005N | R11H 10k, 1% / RESC1005N | SATA_PWRON |
C10H 0.1uF, 6.3V, X5R / CAPC0603N_B | C10H 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | SATA_PWRON |
C10X 0.1uF, 6.3V, X5R / CAPC0603N_B | C10X 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | PCIE_PWRON |
R15L 1k, 1% / REC1005N | R15L 10k, 1% / RESC1005N | LCD_VCC_SW |
C14L 0.1uF, 6.3V, X5R / CAPC0603N_B | C14L 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | LCD_VCC_SW |
C19L 0.1uF, 25V, X5R / CAPC1005N | C19L 1.0uF, 25V, 20% X5R 0201 / CAPC0603N_B | LCD_BL_VDD |
ECO2: FPGA boot fuse interference
FPGA's internal pull-ups on boot will yank boot fuses to the CPU, causing wrong boot source to be selected.
EVT | DVT | Notes |
---|---|---|
R12F 4.7k, 1% / REC1005N | R12F 4.7k, 1% (DNP) / RESC1005N | depop pull-down |
R13F 4.7k, 1% (DNP) / REC1005N | R13F 4.7k, 1% / RESC1005N | populate pull-up |
ECO3: Gbit Ethernet Reset
Default circuit recommended by reference design is bogus. Get rid of it.
EVT | DVT | Notes |
---|---|---|
C32G 10uF, 10V, X5R, 20% | removed | |
D11G BAT54T1G | removed | |
D12G BAT54T1G | removed | |
R20G 10k, 1% | R20G 10k, 1% (DNP) | also changed to pull to ground by default |
ECO4: PCIe power on
Wire PCI express power on line (gate of Q10X) to ball R1 / pad name GPIO_17 / "GPIO7[12] aka 6 * 32 + 12 = GPIO 204". Software change required
ECO5: Improve magnetics termination
The magnetics in the PHY are not terminated properly, causing ISSI.
EVT | DVT | Notes |
---|---|---|
R14G 0 ohm | R14G 0 ohm (DNP) | also move EN1G_3.3VA line to other side of decaps on CT |
ECO6: Gbit reflcock SI
Drive strength of U10G is not strong enough to overcome series terminator. Replace with shunt.
EVT | DVT | Notes |
---|---|---|
R21G 49.9, 1% RESC1005N | R21G 0 ohm RESC1005N | Double-check routing, consider RC shunt terminator |
ECO7: HDMI HPD polarity
HDMI HPD polarity is not software programmable, so need to buffer (not invert) incoming signal.
EVT | DVT | Notes |
---|---|---|
R28L 0 ohm | R28L 0 ohm (DNP) | |
R27L 0 ohm (DNP) | R27L 0 ohm | |
Q17L 2N7002W (DNP) | Q17L 2N7002W | |
R29L 10k, 1% (DNP) | R29L 10k, 1% |
ECO8: Audio chip sucks (power)
During power down, audio chip totally leaks power through the I2C bus. Need to really strengthen the pull-down to fully reset the chip and fight the pull-ups on I2C.
EVT | DVT | Notes |
---|---|---|
R21A 20 ohms, 1%,0402 | 10 ohm on EVT1A, but should be effective at 20 ohms. 10 ohms would be a new component, if lower value is needed go to 8.06 1% (from R10N) |
- APX803-44SAG-7 added, monitoring the P5.0V line, and pulling down the RESETBMCU line.
- add 2.2k resistor in shunt with input capacitor network (BATT_PWR to ground)
- Cut ALRCK trace to U11A, and jumper pin 9 of U11A to LCD_BL_ON
- Rewire LCD_BL_ON to a new GPIO on the i.MX6 (final GPIO TBD)
- Connect PICE_PWRON to i.MX6 (final GPIO TBD)
- DDC_SCL changed to driver-only to prevent DoS attack on device via HDMI port