DP83826E: Forgotten strap resistor on DP83826E = strap 4

Jiri Pospisil

Part Number: DP83826E

Tool/software:

Hi,

I forgot to add a pull-up resistor to pin 28 (COL/LED2/TX_ER/GPIO/Strap4) in the schematic (then also on the PCB). Is it possible to bypass this and activate it somehow via a register? Thank you

datasheet: www.ti.com/.../dp83826e

6 months ago

+1 Alvaro (Al-vuh-roe) Reyes 6 months ago

TI__Mastermind 19621 points

Hi Jiri!

Just to confirm, are you using the DP83826 in Enhanced or Basic Mode?

In Enhanced Mode, Strap 4 configures the PHY_ADD2 bit
- This cannot be changed via register write, the PHY address can only be set via the bootstrap pins
In Basic Mode, Strap 4 helps configure the MAC mode
- RMII or MII can be selected in Reg 0x17[5]

Regards,

Alvaro

0 Jiri Pospisil 6 months ago in reply to Alvaro (Al-vuh-roe) Reyes

Prodigy 30 points

Here is my actual schematic

My pin1 is in LOW. I see from the datasheet that my mode is BASIC.

So writing RCSR register 0x17 to 5 bit value 1 solved my problem? i try it.

0 Jiri Pospisil 6 months ago in reply to Alvaro (Al-vuh-roe) Reyes

Prodigy 30 points

This run my eth phy. Thank you Alvaro

Fullscreen

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HAL_ETH_WritePHYRegister
(&EthHandle, MP_PHY_ADDRESS, 0x17, ((uint16_t)0x0061));
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

HAL_ETH_WritePHYRegister
(&EthHandle, MP_PHY_ADDRESS, 0x17, ((uint16_t)0x0061));

0 Alvaro (Al-vuh-roe) Reyes 6 months ago in reply to Jiri Pospisil

TI__Mastermind 19621 points

Hi Jiri!

You're welcome! Glad that it worked for you!

Regards,

Alvaro

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DP83826E: Forgotten strap resistor on DP83826E = strap 4