DP83630 TPI NETWORK CIRCUIT

Dear Patrick

Thank you

Please, answer

We are trying to communicate with DP83630 via Serial Management Interface, (we looked  the signals on an oscilloscope) but  the DP83630 still does not respond to requests. We tried to read/write to different registers, but  there is no result. We checked the next: if at the RESET_N and PWRDOWN inputs is "0", then internal generator doesn't work, if at the RESET_N and PWRDOWN inputs is "1", then generator works and we see 25 MHz signals at  X1and X2. Then we checked the next: we strapped pin CLK_OUT_EN  pull-up (pin 21) via 2.2k (сycled power then) and see at CLK_OUT pin, but there is not 25 MHz signal at  this pin. Please, give an advice on what could be done in order to understand whether the DP83630 is OK in principle?  Please, see oscillograms.

Write REG 0  PHY 0   Data 0x55

I

I

I

I

READ REG 0   PHY 0

TIA

Sincerely yours

Vladimir Naumenkov

www.agat.by

Vladimir,

Your debug approach is thoughtful and well considered.  You are doing the right things in order to understand the issue.

Regarding the MDIO register access, could you confirm that the Phy Address straps for the Phy agree with the Phy Address in the MDIO sequence?  Are the Phy Address straps set for an address of 0x00? 

Patrick

Dear Patrick

Thank you

Yes, the Phy Address straps for the Phy agrees with the Phy Address in the MDIO sequence. We checked again PHY address 0x00 ( that is we strapped PHYAD0 (42 pin) to 0V via 2.2k and other PHY pins has internal pull-down).  We also checked PHY address 0x01 (that is  PHYAD0- PHYAD4 pins has internal strapping only). We also pull-up MDIO pin via 1.5k resistor. 

We use PIC32 microcontroller (Microchip), it has MIIM interface, which seems to be the same as Serial Management Interface. 

Please, report: 

1. If I understand correctly, we can write the data into the register and then read the same data? 

2.  MDIO pin  first is the input, and at which moment it switches to the output?

3. I wrote earlier that  we checked the next: we strapped pin CLK_OUT_EN  pull-up (pin 21) via 2.2k (сycled power then) and see at CLK_OUT pin, but there is not 25 MHz signal at  this pin.   QUESTION: to obtain a signal of 25 MHz at  CLK_OUT not required to write any data to the internal  registers via Serial Menagement Interface? It only requires  to strap pin CLK_OUT_EN  pull-up ? 

TIA

Yours sincerely

Vladimir Naumenkov

www.agat.by

Dear Patrick

Please, answer:

-can we use "SAU510-USB ISO PLUS JTAG Emulator" with DP83630?

-whether it is necessary after the power on, to set (for a short time) RESET_N  in "0" ?

TIA

Sincerely yours 

Vladimir Naumenkov

www.agat.by

Vladimir,

I am not familiar with the JTAG emulator that you mentioned, but the DP83630 is compliant with the 1149.1 specification so I would not anticipate any problems when using a compliant emulator.

The DP83630 internal circuitry will automatically be reset as part of the power up process.  Note that a reference clock input is required as part of this process.  After power up, it is not necessary to drive the RESET_N pin to 0V as part of the initialization process.

Patrick

Dear Patrick

Thank you.

1. Please, specify, you mean reference clock at  X1 input ?

2. Pin 30 (MDIO): "This pin requires 1.5 k pullup resistor. Alternately, an internal pullup may be enabled by setting  bit 3 in the CDCTRL1 register" . QUESTION: if there is not external pull up resistor, how can we write in CDCTRL1 register - because the Serial Management Interface will not work without this resistor?

Sincerely yours,

Vladimir Naumenkov

www.agat.by