DS280DF810EVM: PRBS User Defined Custom Pattern

Chenxuan Cui

Part Number: DS280DF810EVM
Other Parts Discussed in Thread: DS280DF810, DS560DF810

Hi, I am using the board PRBS generator, I tried PRBS 7 and other patterns and it all worked and I can see the output on the DCA, the eye diagram all looked good. Then I tried custom pattern like 01010101 or 00110011, but when I selected it and set the pattern, the output flatlined, I am not sure why.

Also, I want to make sure that the error count max at 2048? There is no way I can set the registers to count more errors? Thanks !

12 days ago

0 Drew Miller1 12 days ago

TI__Mastermind 40043 points

Hi Chenxuan,

There is a bug with custom pattern selection in SigCon Architect. You need to manually set the custom pattern on the low level page in registers 0x7C, 0x97.

You will also need to replace the default DS280DF810 xml file in SigCon Architect in order to allow write access to 0x7C, 0x97 in SigCon Architect.

Please see this FAQ for detailed information / instructions on this.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/732366/faq-ds280df810-how-to-use-sigconarchitect-to-program-16-bits-user-defined-generator-pattern?tisearch=e2e-sitesearch&keymatch=ds280df810%20%26%26%20user%20pattern#

Yes, error count maxes out at 2048. Please take a look at the programming guide for this device. You will see that the error counter is 11 bits.

Thanks,

Drew

0 Chenxuan Cui 11 days ago

Prodigy 80 points

Thank you! Is there a way to increase the error counter bit width? A maximum of 2048 counts isn’t sufficient for my use case, can the counter capacity be expanded via SigCon or firmware?

Thanks!

0 Drew Miller1 10 days ago in reply to Chenxuan Cui

TI__Mastermind 40043 points

Hi Chenxuan,

No, the counter width is fixed in the digital logic of this device.

The DS560DF810 has a bigger error counter, but configuration of this device is handled through an API written in C.

Thanks,

Drew

0 Chenxuan Cui 10 days ago in reply to Drew Miller1

Prodigy 80 points

Thanks!

Since the error count saturates at 2048 and error rate will be invalid after that, can I set the capture period shorter? Like seconds or mili-seconds? In the SigCon -> High Level Page -> PRBS Gen/Checkr -> Capture Period, I can only set hours and mins.

Thank you !

0 Drew Miller1 10 days ago in reply to Chenxuan Cui

TI__Mastermind 40043 points

Hi Chenxuan,

I'd recommend looking over the programming guide for this device. You can access this at the link below.

https://www.ti.com/drr/opn/DS280DF810-DESIGN

The "capture period" is inherent to SigCon Architect, but not the device. This is just a representation from when you last cleared the PRBS error counter to when you read the PRBS error count. If you use register access, you could reduce the time to seconds, or maybe hundreds of milliseconds. Please see the programming guide for more details on PRBS checker configuration.

Thanks,

Drew

0 Chenxuan Cui 10 days ago in reply to Drew Miller1

Prodigy 80 points

Thanks Drew, I am also exploring the DS560DF810 that you mentioned, I checked its datasheet, but I did not find the pin configuration. I want to know if this chip has the same pin configuration and dimension as the DS280DF810, so I can directly replace it.

Do you know where I can find the pin configuration and function figure for this board? Thanks!

0 Chenxuan Cui 10 days ago in reply to Drew Miller1

Prodigy 80 points

Hi Drew, from the Programmer's Guide, I did not find the register that allow me to edit the PRBS checker capture period, is that a software feature? Could you please let me know how I can change the capture period to one second or less ? Thanks!

0 Drew Miller1 10 days ago in reply to Chenxuan Cui

TI__Mastermind 40043 points

Hi Chenxuan,

You can find full data sheet and programming guide for DS560DF810 here.

https://www.ti.com/drr/opn/DS560DF810-DESIGN

Chenxuan Cui said:
Hi Drew, from the Programmer's Guide, I did not find the register that allow me to edit the PRBS checker capture period, is that a software feature? Could you please let me know how I can change the capture period to one second or less ? Thanks!

Drew Miller1 said:
The "capture period" is inherent to SigCon Architect, but not the device. This is just a representation from when you last cleared the PRBS error counter to when you read the PRBS error count.

The capture period is not a setting on the device. The capture period is the amount of time between when PRBS error counter is cleared and when PRBS error counter is read.

Thanks,

Drew

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DS280DF810EVM: PRBS User Defined Custom Pattern