Hi
As per i.MX8M Mini Datasheet NVCC_ENET supports 1.8V/2.5V/3.3V IO voltage.According to Ethernet PHY (AR8031) used in i.MX8M Mini EVK board, MDC,MDIO are 3.3V only tolerant and in EVK ENET IO (NVCC_ENET) voltage is set to 1.8V (used Voltage Translators for MDC,MDIO pins).
Is there any limitation or issue when we set ENET IO(NVCC_ENET) voltage to 3.3V ?
We want to set NVCC_ENET to 3.3V to avoid Voltage Translator on MDC,MDIO pins with the same Ethernet PHY in our Custom design using i.MX8M Mini & Nano CPU.
Best Regards,
Shruthi Subramanian
Igor,
For the DART-MX8M-MINI, the datasheet (J1.31-No EC of Table 3) shows the voltages for RMII, RGMII, and GPIO. What is the voltage(s) NVCC_ENET for MII (using 4 lines for ENET_RDx and 4 lines for ENET_TDx)?
Regards,
Erik
Hi igor,
Thanks for the reply.I would also like to know as per i.MX8MM Errata "e50080" -
(IO internal pull up/down is not supported in 3.3V mode.For 3.3V IO operation use external resistors for pull up/ pull down and disable the internal pullup/down via software.All IO pin groups are impacted except for XTAL, DDR, PCI, USB, and MIPI PHY IO’s.) whether we need to give External Pullup Resistor Option or not for i.MX8MM all ENET IO signals at CPU side if we are setting NVCC_ENET to 3.3V.
Regards,
Shruthi
Hi Shruthi
according to Table 64. i.MX 8M Mini 14 x 14 mm functional contact assignments
Datasheet MDC,MDIO pins also belong to NVCC_ENET power group.
From i.MX8MM side there are no restrictions for using 3.3V, if phy allows
this voltage also can be used. Setting NVCC_ENET to 3.3V means that all i.MX8MM
enet signals will operate with I/O 3.3V levels.
Best regards
igor
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Hi igor,
Thanks for the reply.I would also like to know as per i.MX8MM Errata
"e50080" -
(IO internal pull up/down is not supported in 3.3V mode.For 3.3V IO
operation use external resistors for pull up/ pull down and disable the
internal pullup/down via software.
All IO pin groups are impacted except for XTAL, DDR, PCI, USB, and MIPI
PHY IO’s.) whether we need to give External Pullup Resistor Option or
not fori.MX8MM all ENET IO signals at CPU side if we are setting
NVCC_ENET to 3.3V.
I If Pull up resistor is needed for 3.3V IO ENET, how much is
recommended Pullup value for ENET Signals?
Regards,
Shruthi
Hi Shruthi
for external pulls one can use the same values as internal.
Best regards
igor