DP83825I: Can't Link Up (Re-Post)

Hi Gerome-san,

I asked the same question in another thread, but I accidentally marked it as "solved" so I'm reposting it.
https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1361159/dp83825i-can-t-link-up/5200415#5200415

As per your instructions, we asked the customer to check the status of the register again.

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When I checked, it seems that the software had overwritten Bit 12 of BMCR to 0x0 to 1.
It is overwritten during initial setup and communication.
I have attached the register contents ⑤ immediately after starting and resetting with RST_N.

Looking at this, LED0 (ANeg_Dis) is fixed at 1:H in STRAP, and when the IC starts up,
0x0: It seems that Bit12 (Auto-Negotiation_Enable) of BMCR can be set to 0.

Further investigation shows that even if 0x0: BMCR Bit12 (Auto-Negotiation_Enable) is overwritten to 1, whether the link is successful or not changes depending on the state of the LED0 pin (1:H fixed or 0:L fixed).
If 1:H is fixed, the link is currently 100% successful.
If 0:L is fixed, linking will fail about 70% of the time.

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Reg <00> = 0x2100
Reg <01> = 0x7849
Reg <02> = 0x2000
Reg <03> = 0xA140
Reg <04> = 0x0181
Reg <05> = 0x0000
Reg <06> = 0x0004
Reg <07> = 0x2001
Reg <08> = 0x0000
Reg <09> = 0x0000
Reg <0a> = 0x0100
Reg <0b> = 0x0000
Reg <0c> = 0x0000
Reg <0d> = 0x0000
Reg <0e> = 0x0000
Reg <0f> = 0x0000
Reg <10> = 0x0004
Reg <11> = 0x0108
Reg <12> = 0x0000
Reg <13> = 0x0000
Reg <14> = 0x0000
Reg <15> = 0x0000
Reg <16> = 0x0100
Reg <17> = 0x00E1
Reg <18> = 0x0400
Reg <19> = 0x0000
Reg <1a> = 0x0000
Reg <1b> = 0x007D
Reg <1c> = 0x05EE
Reg <1d> = 0x0000
Reg <1e> = 0x0102
Reg <1f> = 0x0000
Reg <0467> = 0x043A

Is it correct behavior for Link to succeed or fail depending on the state of the LED0 pin? (I'm sorry I don't understand clearly.)

Best regards,
Hiroshi