TLK10232 10G transceiver startup

Hi Michael,

For KR using manual mode settings learned from Link Training with 156.25 MHz / 312.5MHz Refclk without Auto-Negotiation, please try this procedure:

1. Pin configuration:

Ensure ST input pin is Low

Ensure MODE_SEL input pin is Low

Ensure PRBSEN input pin is Low

Ensure REFCLK_SEL input pin is Low

2. Reset Device:

Issue a hard or soft reset (RESET_N asserted for at leaste 10us or write 1'b1 to 30.0.15)

3. REFCLK input frequency and selection:

156.25MHz / 312.5MHz (Write to 30.29.12)

REFCLKx_P/N used (Write to 30.1.1)

4. Write 0x2000 to 7.0 (Disable Auto Negotiation)

Write 0x2000 to 30.150 (Enable Link Training)

Write 0x0000 to 0x1.9002 (MS bits) & 0x1.9003 (LS bits) Disable a 500ms time-out-counter to avoid issues with having LT start at independent times for each side of the link.

Write 0x0008 to 30.14 (Data-path Reset)

***Wait 1000ms

5. Read 30.151 (LT_TRAIN_STATUS) to verify the status of link training process

6. If Link Training is succesfull, then you need to read out the best settings for the pre and post cursor de-emphasis:

There is a mechanism in the TLK10xxx devices to read out the results of a link training sweep.  This can be used as a quick link margin measurement, since it indicates whether or not the receiver detected errors across a large number of combinations of transmitter pre-cursor and post-cursor de-emphasis levels.

During link training, the receiver will instruct the transmitter to iterate through different combinations of settings.  At each setting, the transmitter sends test packets and the receiver detects whether or not there are errors.  Once a point is tested, the receiver asks the transmitter to go on to the next setting.  The settings here are the pre-cursor tap and the post-cursor tap of a 3-tap FIR de-emphasis filter (this is a standard transmitter implementation, and an example of it is shown in the presentation I sent you).

Here is the procedure to read out these test results:

1. Write 1’b1 to 0x01.9001 bit 12.  This sets a pointer to the link training results that correspond to the minimum post-cursor de-emphasis level.  This sort of initializes the read-out process.

2. Read register 0x01.9022.  This contains the BER data for all pre-cursor de-emphasis levels for the minimum post-cursor de-emphasis level.  The first 8 bits will always be high, but the lowest 8 bits indicate the presence (1) or absence (0) of errors during the testing at that point.

3. If you read register 0x01.9022 again, you will get the results for all the different pre-cursor levels at the next available post-cursor level.  Each read will increment the post-cursor level, so you will need to read this register over and over (16 times) and record the values to be able to see results for every different combination.  I can help interpret these results, but basically what we are looking for is how many points have the value “0” instead of “1” – lots of points with no errors would indicate a link operating with good margin.

This is all that is needed for TLK10232.  

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Regarding to SFP+ (settings):

As you know, every system is different, so basically, user needs to perform a tuning of the device to get the best combination for their system requirements.

Attached you will find a guideline for this settings.6685.TLK10034_link_training_app_note (10).doc

I hope this helps.

Please try this, and let me know the response of the device.

Best Regards!

Luis Omar Morán Serna

High Speed Interface

SWAT Team