DP83867E: BIST PBRS Checker Failing to Increment Byte Counters in Analog Loopback Mode

George Dagis

Part Number: DP83867E

Hi all,

I am using a DP83867E and attempting to use the BIST feature. I initialize the PHY with a reset and then simply enable the PRBS packet generator (reg 0x16 bit 12) with default values for IPG and packet length. I do not see the bytes received registers incrementing. Here is a dump of my registers after I end the BIST: Please note bit 14 in register 0x00 and bit 2 in register 0x16 are enabled (digital loopback enable).

0x00	0x00004000
0x01	0x00007949
0x02	0x00002000
0x03	0x0000a231
0x04	0x000001e1
0x05	0x00000000
0x06	0x00000064
0x07	0x00002001
0x08	0x00000000
0x09	0x00000300
0x0A	0x00000000
0x0B	0x00000000
0x0C	0x00000000
0x0D	0x0000401f
0x0E	0x0000f500
0x0F	0x00003000
0x10	0x00005848
0x11	0x00000802
0x12	0x00000000
0x13	0x00000400
0x14	0x000029c7
0x15	0x00000000
0x16	0x00000004
0x17	0x00000040
0x18	0x00006150
0x19	0x00004444
0x1A	0x00000002
0x1B	0x00000000
0x1C	0x00000000
0x1D	0x00000000
0x1E	0x00000002
0x1F	0x00000000

0x25:	0x00000400
0x2C:	0x0000141f
0x2D:	0x00000000
0x2E:	0x00000221
0x31:	0x000010b0
0x32:	0x000000d3
0x33:	0x00000000
0x37:	0x00000003
0x43:	0x000007a0
0x53:	0x00002055
0x55:	0x00000000
0x6E:	0x00000801
0x6F:	0x00000100
0x71:	0x00000000
0x72:	0x00000000
0x7B:	0x000005dc
0x7C:	0x0000007d
0x86:	0x00000077
0xC6:	0x00000000
0xD3:	0x00000000
0xE9:	0x00009f22
0xFE:	0x0000e721
0x12C:	0x00000c2d
0x134:	0x00001000
0x135:	0x00000000
0x136:	0x00000000
0x137:	0x00000000
0x138:	0x00000000
0x139:	0x00000000
0x13A:	0x00000000
0x13B:	0x00000000
0x13C:	0x00000000
0x13D:	0x00000000
0x13E:	0x00000000
0x13F:	0x00000000
0x140:	0x00000000
0x141:	0x00000000
0x142:	0x00000000
0x143:	0x00000000
0x144:	0x00000000
0x145:	0x00000000
0x146:	0x00000000
0x147:	0x00000000
0x148:	0x00000000
0x149:	0x00000000
0x14A:	0x00000000
0x14B:	0x00000000
0x14C:	0x00000000
0x14D:	0x00000000
0x14D:	0x00000000
0x14E:	0x00000000
0x14F:	0x00000000
0x150:	0x00000000
0x151:	0x00000000
0x152:	0x00000000
0x153:	0x00000000
0x154:	0x00000000
0x155:	0x00000000
0x156:	0x00000000
0x157:	0x00000000
0x158:	0x00000000
0x159:	0x00000000
0x15A:	0x00000000
0x15B:	0x00000000
0x15C:	0x00000000
0x15D:	0x00000000
0x15E:	0x00000000
0x15F:	0x00000000
0x161:	0x0000000c
0x16F:	0x00000095
0x170:	0x00000c0b
0x172:	0x00000000
0x180:	0x00000752
0x190:	0x00000000
0x191:	0x00000000
0x192:	0x00000000
0x193:	0x00000000
0x194:	0x00000000
0x195:	0x00000000
0x196:	0x00000000
0x197:	0x00000000
0x198:	0x00000000
0x199:	0x00000000
0x19A:	0x00000000
0x19B:	0x00000000
0x19C:	0x00000000
0x19D:	0x00000000
0x19E:	0x00000000
0x19F:	0x00000000
0x1A0:	0x00000000
0x1A1:	0x00000000
0x1A2:	0x00000000
0x1A3:	0x00000000
0x1A4:	0x00000000
0x1D5:	0x0000f500

Thanks in advance,

George

over 2 years ago

0 Kallikuppa Sreenivasa over 2 years ago

TI__Guru** 121988 points

Hello George,

Thank you for the query.

Please check if you have selected the Loopback Mode and enabled the LOOPBACK.

Regards,

Sreenivasa

0 George Dagis over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 30 points

Apologies, my original table didn't have the correct values. Please review again (both of those bits are enabled). Thanks!

0 Kallikuppa Sreenivasa over 2 years ago in reply to George Dagis

TI__Guru** 121988 points

Hello George.

Thanks you for the update. Please refer the below app note for reference.

Application note

DP83867 Troubleshooting Guide (Rev. A)

Have you connected any cable to test the external loopback?

Regards,

Sreenivasa

0 George Dagis over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 30 points

Hi Sreenivasa,

Upon boot, instead of enabling digital loopback (bit 2 in reg 0x16), loopback (bit 14 in reg 0x00) and BIST packet generator (bit 12 in reg 0x16) I enabled reverse loopback (bit 5 in reg 0x16) can see traffic coming back via wireshark.

0 Kallikuppa Sreenivasa over 2 years ago in reply to George Dagis

TI__Guru** 121988 points

Hello George,

Good to hear on the progress .

Regards,

Sreenivasa

0 George Dagis over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 30 points

Yes, I've been able to do reverse loopback but still nothing from the BIST packet generator in digital loopback mode. Do you have any suggestions?

0 Kallikuppa Sreenivasa over 2 years ago in reply to George Dagis

TI__Guru** 121988 points

Hello George,

Did you read through the debug guide and did that help.

Also, can you enable loopback and try different loop back configurations to check if any of the loopback works.

Regards,

Sreenivasa

0 George Dagis over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 30 points

Hi Sreenivasa,

Various loopback modes sending from an external source:

Reverse - Loopback works with bit 14 in register 0 off ONLY

External - Nothing regardless

Analog - Nothing regardless

Digital - Nothing regardless

0 Kallikuppa Sreenivasa over 2 years ago in reply to George Dagis

TI__Guru** 121988 points

Hello George,

Could you please elaborate your inputs.

Also can you please sketch a simple diagram to show your test setup.

Regards,

Sreenivasa

0 George Dagis over 2 years ago in reply to Kallikuppa Sreenivasa

Prodigy 30 points

Hi,

I am using a stable linux machine using 64-byte packets over tcpreplay to send directly to the TI platform. I've seen passthrough through my application, as well as reverse loopback work as expected.

0 Kallikuppa Sreenivasa over 2 years ago in reply to George Dagis

TI__Guru** 121988 points

Hello George,

Can i assume you are doing the loopback from the MDI side. If yes, only reverse loopback will work.

Did you try doing the loopback from the MAC side?

egads,

Sreenivasa

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DP83867E: BIST PBRS Checker Failing to Increment Byte Counters in Analog Loopback Mode