DP83869HM: LED is Not blink

In this project we didn't used MCU, only used Ethernet IC, Pls suggest in hardware how can i bring up LED

Hello,

If the PHY is under default conditions (ie no programming made), then the LED's will act as the following:

LED0: Link

LED1: 1G Link

LED2: Activity

If this is the following, then 2 situations come to mind, assuming the PHY is set up correctly (power rails good, clk_out on, activity on the MDI line, etc):

1) You are not getting link. This would explain why LEDs are not turning on, but it is harder to debug as you do not have register access available. What is the link partner you are connecting to in this case? What cabling is being used (type and length)?

2) LED driver is active high. In datasheet section 9.5.2, LED configuration states that "If a given strap input is resistively pulled low then the corresponding output is configured as an active high driver." If you are getting link, then the LED pin would be driven high, while would cause the LED to turn off as there isn't sufficient voltage difference to satisfy LED turn-on voltage. This would require a change in layout to fix, or register access to make the pin an active low.

Sincerely,

Gerome

Hello Gerome,

DP83869HM any software required for this IC?

Regards,

Rajesh R

Hi Rajesh,

TI offers SMI tool for MSP430 which is connected to our PHY called USB2MDIO. Otherwise, any microcontroller that supports SMI communication can help, but you would need to figure out how to program that procedure.

Sincerely,

Gerome

Thanks for replying!!!

We have configured the PHY in copper to SGMII mode which have below boot strap configurations.

JTAG TDO(PIN 22): OPEN

RX-D2(PIN 35): PULLED  TO VDDIO WITH 2.49K RES

RX-D3 (PIN 36): PULLED TO VDDIO WITH 2.49K RES

Strap setting for functional modes:

1. LED0: Pulled to ground with 2.49K resistor

2. LED1: Pulled to ground with 2.49K resistor

3. LED2: Pulled to ground with 2.49K resistor

We have powered up and checked the voltage across the  LED strap resistor which is 0V.

We could not able to establish the link at 100BASE-TX and SGMII.

Please verify the above straps, whether we have configured for Copper to SGMII or not.

Also, Help us to bringup the PHY.

Thanks.

Hello Rajesh,

I will be out of office for the rest of the week. I have this discussion queued up to bring up with team upon my return. Please expect a response by early next week. Thank you for your patience.

Sincerely,

Gerome

Hi Rajesh,

Your strapping looks fine. Those are the intended configurations. I would advise checking those pins while holding the PHY in reset state to ensure that nothing else is trapping the PHY that would have it deviate from these settings on these pins.

Can you also measure CLKOUT pin to ensure signal is within specifications as required in datasheet?

For further debug, it will be difficult to go further without microcontroller to look at register configuration to see if link is up from register standpoint.

Sincerely,

Gerome