TJA1102 remote WKU/LPS forwarding

Markovic — Mon, 14 Oct 2024 21:22:12 GMT

Hi!

Following situation:
- Two automotive eth (E1 and E2) are in communication
- To sniff the traffic device with TJA1102 dual PHY is inserted in between
- The phy works in RMII_mode = "10", RMII mode enabled (25 MHz XTAL output on Px_REF_CLK) and reverse mii mode is also an option ( RMII_mode = "11" )
- The traffic sent from "E1" arrives on the PHY A of TJA1102, it isforwarded to a PHY B placed in the same TJA1102 package where from it is forwarded to the E2.
- Problem arrives when I come to remote WAKE UP and SLEEP forwarding. If E1 sends WKU request, I expect TJA1102 PHY A to receive it, forward it to the PHY B, which would send request (or pulses depending on the link status) to the E2. TJA1102 should stay in normal power mode and should just forward the requests ....
To achieve this following register fields values are set:

- FWDPHYLOC       = 0 ( do not want request to have influence on the sniff device )
- REMWUPHY         = 1
- LOCWUPHY         = 0 ( not using local wku/sleep at the moment)
- SLEEP_CONFIRM = 1 ( E1 needs approval from E2 to go to SLEEP mode)
- LPS_WUR_DIS     = 0
- SLEEP_ACK          = 1
- FWDPHYREM        = 1
- LPS_ACTIVE          = 1

This is the config for both PHYs in TJA1102 package. I am expecting the requests to be passed from one PHY to the other one in the package internally ( I was expecting when the PHY is in reverse MII mode, working as a repeater, it would work, but it does not. If E1 initiates the request it does not reach E2 (all interrupts are enabled, checking Remote_wakeUp and LPS_received register fields).

Is there something I am missing here, or this should achieve in different way.

Thank You very much,
Nebojsa

topic TJA1102 remote WKU/LPS forwarding in NXP Designs

TJA1102 remote WKU/LPS forwarding