I'm designing a schematic for RT1170 application board.
I'd like to connect an Ethernet phy device by RMII, so I refer to Table 61-66 in reference manual.
However I couldn't understand what pin I should connect to the CRS/DV pin of my ethernet phy device.
As far as I checked, I think "RX_DV" port should be connected to the CRS/DV pin of my ethernet phy device. But I couldn't find ports corresponding to "RX_DV" on Table 11-1 in Chip IO chapter.
On the other hand, "RMII_CRS_DV" signal on Figure 60-21 looks the same as what I want to use.
However I couldn't find the port either on Table 11-1 in Chip IO chapter.
What pin should I connect to the CRS/DV pin of my ethernet phy device?
Hi @Eugene3,
The signal you are looking for is the ENET_RX_EN signal, which should be routed to GPIO_DISP_B2_08. This pin works as the CRS_DV pin in RMII mode, but also as RX_DV pin in the MII mode. This is why the naming scheme follows a more general "RX enable".
We can corroborate this on the MIMXRT1170-EVKB Schematic:
I hope this helps!
BR,
Edwin.
Hi @EdwinHz
Thank you for your information.
I understand I'll connect ENET_RX_EN signal for CRS_DV.
But how can I know ENET_RX_EN port plays the role of CRS_DV in RMII mode from reference manual?
Once I searched "RX_EN" in reference manual, I found RX_EN is for only RGMII on Table 61-66. It's confusing.
"RX_EN" and "ENET_RX_EN" have different meanings, right?
Hi @Eugene3,
RX_EN and RX_DV are the same signals. The Reference Manual tries to separate them for different interface naming schemes, but as you can see, the RX_EN signal contains the RX_DV.
Anyhow, merging the RX_EN and RX_DV has been proposed for a better understanding of this signal. You can consider the table as follows:
Finally, RX_EN is the name of the signal from the ENET module, while ENET_RX_EN is the name that refers to the pad that drives the RX_EN signal from the module. For all intents and purposes they are the same.
I understand the current state of the documentation can cause confusion about this topic, and I apologize for that. This issue has already been reported internally but the documentation change is yet to be implemented on a future release of the RT1170 Manual. For now, I hope I cleared things up about this issue.
BR,
Edwin.
Hi @Eugene3,
The signal you are looking for is the ENET_RX_EN signal, which should be routed to GPIO_DISP_B2_08. This pin works as the CRS_DV pin in RMII mode, but also as RX_DV pin in the MII mode. This is why the naming scheme follows a more general "RX enable".
We can corroborate this on the MIMXRT1170-EVKB Schematic:
I hope this helps!
BR,
Edwin.
