DAC38RF82: How does 81180 mode send data in Vivado 204B corre

Jim，

It has been confirmed that the group frames are ok.But I'm not sure if it's a configuration issue.When testing a single frequency signal, multiple tones are output.Attach information.

A0     8'h18
A1     8'h30
A2     8'h46
A3     8'h59
A4     8'h69
A5     8'h75
A6     8'h7C
A7     8'h7E
A8     8'h7C
A9     8'h75
A10    8'h69
A11    8'h59
A12    8'h46
A13    8'h30
A14    8'h18
A15    8'h00
A16    8'hE8
A17    8'hD0
A18    8'hBA
A19    8'hA7
A20    8'h97
A21    8'h8B
A22    8'h84
A23    8'h82
A24    8'h84
A25    8'h8B
A26    8'h97
A27    8'hA7
A28    8'hBA
A29    8'hD0
A30    8'hE8
A31    8'h00

0x00 0x5860
0x01 0x3080
0x02 0xFFFF
0x03 0xFFFF
0x04 0x00FE
0x05 0x0007
0x40A 0x7C03
0x40B 0x0022
0x40C 0xA002
0x40D 0xF000
0x41B 0x0000
0x423 0xFFFF
0x424 0x1001
0x431 0x1000
0x432 0x0508
0x433 0x453C
0x434 0x0000
0x435 0x0018
0x43B 0x1802
0x43C 0x8229
0x43D 0x0088
0x43E 0x0909
0x43F 0x0000
0x10A 0x8050
0x10C 0x2402
0x10D 0x0000
0x10E 0x00FF
0x10F 0xFFFF
0x110 0xFFFF
0x111 0xFFFF
0x117 0x0000
0x119 0x0001
0x11C 0x0000
0x11D 0x0000
0x11E 0x0000
0x11F 0x0000
0x120 0x0000
0x121 0x0000
0x122 0x0000
0x123 0x0000
0x124 0x0030
0x125 0x3000
0x127 0x8888
0x128 0x0330
0x129 0x0000
0x12A 0x0000
0x12B 0x0000
0x12C 0x0000
0x12D 0x1FFF
0x12E 0x1FFF
0x12F 0x0000
0x130 0x0000
0x132 0x0400
0x133 0x0400
0x146 0x0044
0x147 0x190A
0x148 0x31C3
0x14A 0xFF03
0x14B 0x0700
0x14C 0x0707
0x14D 0x0007
0x14E 0x0F0F
0x14F 0x1CC1
0x150 0x0000
0x151 0x00FF
0x152 0x00FF
0x153 0x0000
0x154 0x0CE7
0x15C 0x0002
0x15E 0x0000
0x164 0x0000
0x165 0x0000
0x166 0x0000
0x167 0x0000
0x168 0x0000
0x169 0x0000
0x16A 0x0000
0x16B 0x0000
0x16C 0x0000
0x16D 0x0000
0x16E 0x0000
0x20A 0x8050
0x20C 0x2402
0x20D 0x0000
0x20E 0x00FF
0x20F 0xFFFF
0x210 0xFFFF
0x211 0xFFFF
0x217 0x0000
0x219 0x0001
0x21C 0x0000
0x21D 0x0000
0x21E 0x0000
0x21F 0x0000
0x220 0x0000
0x221 0x0000
0x222 0x0000
0x223 0x0000
0x224 0x0020
0x225 0x3000
0x227 0x8888
0x228 0x0330
0x229 0x0000
0x22A 0x0000
0x22B 0x0000
0x22C 0x0000
0x22D 0x1FFF
0x22E 0x1FFF
0x22F 0x0000
0x230 0x0000
0x232 0x0400
0x233 0x0400
0x246 0x0044
0x247 0x190A
0x248 0x31C3
0x24A 0x0003
0x24B 0x0700
0x24C 0x0700
0x24D 0x0007
0x24E 0x0F0F
0x24F 0x1CC1
0x250 0x0000
0x251 0x00FF
0x252 0x00FF
0x253 0x0000
0x254 0x0CE7
0x25C 0x0003
0x25E 0x0000
0x264 0x0000
0x265 0x0000
0x266 0x0000
0x267 0x0000
0x268 0x0000
0x269 0x0000
0x26A 0x0000
0x26B 0x0000
0x26C 0x0000
0x26D 0x0000
0x26E 0x0000
0x124 0x0000
0x15C 0x0000
0x109 0x0004
0x10A 0xFC03
0x10A 0x7C03
0x00 0x5863
0x124 0x0010
0x15C 0x0003
0x00 0x5860
0x04 0x0000
0x05 0x0000
0x164 0x0000
0x165 0x0000
0x166 0x0000
0x167 0x0000
0x168 0x0000
0x169 0x0000
0x16A 0x0000
0x16B 0x0000
0x16C 0x0000
0x16D 0x0000

Wuge,

What is the DAC clock sample rate? What is the LMFS setting? What SYSREF frequency are you using? What is the K and RBD values? What is the interpolation factor? Is the DAC using real data or I/Q data? One I/Q per channel or two? Are you using the DAC PLL? Are you reporting an errors? Are you using the NCO?

This info is in the config file you send but would take some time to get the info. Providing these answers will help me get back to you sooner.

Is the data file attached what you are sending to the DAC? Please also send a screen shot of the DAC output.

What is the group frame you are mentioning? Is the lane data sent from your FPGA?

Regards,

Jim

Jim，

  Sample rate is 6400 Mhz.LMFS(8118).SYSREF frequency is 1 Mhz ,K = 8 RBD =8.interpolation=1X.real mode..No error.DAC PLL is not used.NCO is not used.

A0 8'h18
A1 8'h30
A2 8'h46
A3 8'h59
A4 8'h69
A5 8'h75
A6 8'h7C
A7 8'h7E
A8 8'h7C
A9 8'h75
A10 8'h69
A11 8'h59
A12 8'h46
A13 8'h30
A14 8'h18
A15 8'h00
A16 8'hE8
A17 8'hD0
A18 8'hBA
A19 8'hA7
A20 8'h97
A21 8'h8B
A22 8'h84
A23 8'h82
A24 8'h84
A25 8'h8B
A26 8'h97
A27 8'hA7
A28 8'hBA
A29 8'hD0
A30 8'hE8
A31 8'h00

This is my test data.

Regards,

Wuge

Jim，

• The picture is the result of my test

Regards,test.docx

Wuge

Wuge,

According to the JESD204B standard, the following equation must be satisfied;   17 <  F * K < 1023.

Your K value is to low. Since F = 1, change K to 20. Give this a try. make sure to change this in the FPGA as well.

Regards,

Jim 

Jim ，

Performance in DAC38RF82 81180 mode is encouraging.The value read in register 0x64 is 0x0002.On our board, we have two DAC38RF82. How to achieve synchronization?

0x00 0x5860
0x01 0x3080
0x431 0x1000
0x43B 0x1802
0x43C 0x8229
0x10A 0x8010
0x10D 0x0000
0x119 0x0001
0x124 0x0030
0x125 0x3000
0x14A 0xFF03
0x14B 0x1300
0x14C 0x1307
0x14D 0x0007
0x14E 0x0707
0x14F 0x1C60
0x151 0x001F
0x153 0x0000
0x154 0x1CE7
0x24A 0x0003
0x124 0x0000
0x15C 0x0000
0x109 0x0004
0x10A 0xFC03
0x10A 0x7C03
0x109 0x0000
0x100 0x5863
0x109 0x0001
0x124 0x0020
0x15C 0x0003
0x109 0x0000
0x100 0x5860
0x109 0x0000
0x104 0x0000
0x105 0x0000

This is my configuration, 20ms interval per write register.dac clk=6400Mhz,sysref=1Mhz .DAC PLL is not used.My problem is that I now need to write 0x0000 to 0x15C to get the output.I tried to write 0x0000 to 0x15C to get the output after the mode was configured, but the synchronization problem was not solved.

Regards,

Wuge

Hi Wuge,

To get the DACs properly synchronized you will have to use SYSREF. So writing 0x0 to 0x15C will cause them to not synchronize. Seeing that you have to write that to get an output may indicate that you are having a problem with the SYSREF. 

One test to verify the DAC is capturing the SYSREF correctly is to test the output with the NCO. I attaching a power point that will guide you through the procedure.

8546.SYSREF_NCO.pptx

Regards,

David Chaparro

Hi David Chaparro,

        Since I don't have an EVM board right now.How do I get NCO only output？I wonder if there is something wrong with my SYSREF frequency.The value I read back from address 0x05 is 0x0139. Is that a problem?

Regards,

Hi,

In order to perform the test mentioned above you will need theses register writes:

Hi, David Chaparro

        Tried with your method and failed to get output.My sampling clock is 6400MHZ.SYSREF is 1MHZ.The value of address 0x05 is 0x0139 what does that mean.

Hi Wuge,

I was looking at your register settings and noticed that you were writing 0x7C03 to address 0x10A. This changes the interpolation of DAC A to a value not supported in this mode. You have a different value written to it before, 0x8050, which works with this mode. Can you try the NCO test with the value of 0x8050 for register 0x10A.

Regards,

David

Hi，David

0x00 0x5860
0x01 0x3080
0x431 0x1000
0x43B 0x1802
0x43C 0x8229
0x10A 0x8010
0x10D 0x0000
0x119 0x0001
0x124 0x0030
0x125 0x3000
0x14A 0xFF03
0x14B 0x1300
0x14C 0x1307
0x14D 0x0007
0x14E 0x0707
0x14F 0x1C60
0x151 0x001F
0x153 0x0000
0x154 0x1CE7
0x24A 0x0003
0x124 0x0000
0x15C 0x0000
0x109 0x0004
0x40A 0xFC03
0x40A 0x7C03
0x109 0x0000
0x100 0x5863
0x109 0x0001
0x124 0x0020
0x15C 0x0003
0x109 0x0000
0x100 0x5860
0x109 0x0000
0x104 0x0000
0x105 0x0000

 This is my configuration. Is there any problem？

Regards,

Wuge

Hi，David

      Even if I configure it like this, there is still no output.I still need to write 0x00 to 0x5C to get the output.Is there a problem with my sysref, but I don't know where the adjustment can be improved.

Regards,

Wuge

Hi Wuge,

Can you share a capture of the output after you make that register write?

Thanks,

David