DS90UB964-Q1: Frequency Counter, RX_FREQ_HIGH & RX_FREQ_LOW

Kenichiro

Part Number: DS90UB964-Q1
Other Parts Discussed in Thread: DS90UB962-Q1

[ DS90UB964-Q1 ] Frequency Counter, RX_FREQ_HIGH & RX_FREQ_LOW

Hi,

My customer try to read and convert the readout value of RX_FREQ_HIGH & RX_FREQ_LOW to actual frequency value, however the calculated value does not match with actual frequency. See the table below.

Case 1

Register	0x4F RX_FREQ_HIGH	0x50 RX_FREQ_LOW
Readout Value	0x35	0x5C
Calculated Frequency	53	359375

53.359375MHz

Case 2

Register	0x4F RX_FREQ_HIGH	0x50 RX_FREQ_LOW
Readout Value	0x33	0x5b
Calculated Frequency	51	35546875

51.35546875MHz

For both cases, actual PCLK is higher than 90MHz, thus don't match.
Can you please let me know whether this conversion is valid?

Note: REFCLK is 23MHz.

Thanks,
Ken

over 6 years ago

0 Hamzeh Jaradat over 6 years ago

TI__Guru* 94420 points

Hello Ken,

These are RX port specific registers. The FPD-Link III Port Select register 0x4C configures which unique Rx port registers can be accessed by I2C read and write commands.
Also make sure which Device revision are you using (reg 0x03), it may not work correctly in the earlier samples.

0 Kenichiro over 6 years ago in reply to Hamzeh Jaradat

Mastermind 9165 points

Hi Hamzeh,

Thank you for your support.
I did check whether customer uses the valid port select register. It seems okay.

For Port 0:
0x4C: 0x01

For Port 1:
0x4C: 0x12

However, with regards to the Revision ID(0x03), the readout value was 0x40.

Do you know this revision ID? Also, do you think the frequency counter has some kind of limitation from this revision?
I'm asking my sales team what kind of samples we did provide to this customer.

Thanks,
Ken

0 Hamzeh Jaradat over 6 years ago in reply to Kenichiro

TI__Guru* 94420 points

Hello Ken,

Revision ID = 0x40 is the newly released UB960 not the UB964.

0 Kenichiro over 6 years ago in reply to Hamzeh Jaradat

Mastermind 9165 points

Hi Hamzeh,

Thank you for the confirmation. hmm...it's strange, what we have suggested is DS90UB962-Q1.
Let me check with our sales team.

Regards,
Ken

0 Kenichiro over 6 years ago in reply to Kenichiro

Mastermind 9165 points

Hamzeh,

Can you please double check the following findings?
As far as my customer checked, it seems that the description of Frequency Counter in the datasheet is for 25MHz REFCLK, and it's not accurate for 23MHz REFCLK.

Thanks,
Ken

0 Kenichiro over 6 years ago in reply to Kenichiro

Mastermind 9165 points

Hello Hamzeh,

Can you please take a look my post above?

Thanks,
Ken

0 Dac Tran over 6 years ago in reply to Kenichiro

TI__Expert 7395 points

Hi Ken-san,

The 0x4f~0x50 FREQ_CNT_HIGH/LOW value is expected. The register value reads back the effective FPD3_PCLK frequency which depends on the operating mode; see note (2) in UB964 datasheet on page 10. Since the frequency is half the input UB913A PCLK, then the operating mode is RAW10. All the UB964 internal timers are referenced using the 25MHz (nominal) REFCLK input. If a 23MHz is used (instead of 25MHz), the frequency ratio would be scaled 25/23 of the measured PCLK.

-Dac

0 Kenichiro over 6 years ago in reply to Dac Tran

Mastermind 9165 points

Hi Dac,

Thank you for sharing good information! It's helpful to understand the function!!

Regards,
Ken

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DS90UB964-Q1: Frequency Counter, RX_FREQ_HIGH & RX_FREQ_LOW

[ DS90UB964-Q1 ] Frequency Counter, RX_FREQ_HIGH & RX_FREQ_LOW