DP83TG720EVM-MC: register writing value mismatch

Chuqiang Wen

Part Number: DP83TG720EVM-MC
Other Parts Discussed in Thread: MSP-EXP430F5529LP, , USB-2-MDIO

Hi expert,

I have some questions from my customer. Please kindly give me a support.

1) Customer is using DP83TG720EVM-MC and MSP-EXP430F5529LP for evaluating currently. After respective initializing registers, customer tried to write 0x2000 value into 0x0904 register into test mode. Read-back value is 0400. If write 0x4000, read-back value is 0800. Could you please kindly give some comments for this phenomenon?

2) We want to use MSP-EXP430F5529LP LaunchPad to connect with 100M TC811 for evaluation, is it work?

3) Customer is using 1.8V in their PCB(TC811 device), So I want to check if LaunchPad can support both 1.8V or 3.3V? How to config I/O voltage?

Thanks!

Best Regards,

Ethan Wen

over 4 years ago

0 Vikram Sharma over 4 years ago

TI__Genius 16030 points

Hello Ethan,

1. Kindly share the read/write procedure. Is customer using usb-2-mdio to read/write registers? Is customer taking care of MMD? For test mode MMD1, x0904 is the register to be written.

2. Yes MSP can be used to control MDC/MDIO.

3. Launch pad does not support 1.8V. But I am checking for the possible work-around and will get back to you.

Regards,

Vikram

0 Chuqiang Wen over 4 years ago in reply to Vikram Sharma

TI__Expert 5865 points

Hi Vikram,

Vikram Sharma said:
1. Kindly share the read/write procedure. Is customer using usb-2-mdio to read/write registers? Is customer taking care of MMD? For test mode MMD1, x0904 is the register to be written.

Yes, customer set MMD1 before writing data in 0x0904. Please see below procedure, last two lines.

Is it correct? What’s the reason?

Or do you have the examples to config 720 into test mode 6(droop test)?

// Title: 720 OA test

begin

//delay 100

000D 401F // restart core

001F 8000

0573 0101

000D 4001

0834 C001

000D 401F

0405 5800

08AD 3C51

0894 5DF7

08A0 09E7

08C0 4000

0814 4800

080D 2EBF

08C1 0B00

087D 0001

082E 0000

0837 00F4

08BE 0200

08C5 4000

08C7 2000

08B3 005A

08B4 005A

08B0 0202

08B5 00EA

08BA 2828

08BB 6828

08BC 0028

08BF 0000

08B1 0014

08B2 0008

08EC 0000

08C8 0003

08BE 0201

018C 0001

001f 4000

0573 0001

056A 5F41

000D 4001

0904 C000

end

Thanks!

Best Regards

Ethan Wen

0 Vikram Sharma over 4 years ago in reply to Chuqiang Wen

TI__Genius 16030 points

Ethan,

No the method to write MMD1, 0904 is not correct. Correct way to write a MMD1 register is as using following :

000D 0001

000E register-address

000D 4001

000E register-value

For MMD1F you may use the similar format :

000D 001F

000E register-address

000D 401F

000E register-value

As you are writting multiple registers of different MMDs in single script you should use above format to write all the register and select "extended register" option = "no" in USB-2-MDIO Gui.

Also to make MSP work with 1.8V vddio domain 811, you will have to use the following setup:

Regards,

Vikram

0 Chuqiang Wen over 4 years ago in reply to Vikram Sharma

TI__Expert 5865 points

Hi Vikram,

Customer followed the instruction and wrote two registers as below:

000D 001F // restart core

000E 001F

000D 401F

000E 8000

000D 001F

000E 0573

000D 401F

000E 0101

But readback value is not correct. Writing is as below:

Readback is as below:

First two are not correct, 001F should be 8000, but 0000 instead, 0574 should be 0101, but 0001 instead.

Thanks!

Best Regards

Ethan Wen

0 Vikram Sharma over 4 years ago in reply to Chuqiang Wen

TI__Genius 16030 points

Ethan,

001F is self clearing register. Written value will get erased.

000D 001F

000E <register address>

000D 401F

000E

Also I see that in above snapshot of usb-2-mdio gui many registers are being written without taking care of the correct write format I shared earlier : 0834, 0405 etc.

Regards,

Vikram

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DP83TG720EVM-MC: register writing value mismatch