DPCD register of PTN3356

[masahirokiniwa]

HI,

Could you tell me the detail of DPCD registers on PTN3356?

Its data sheet explained only PTN3356 specific DPCD registers.

But I think that PTN3356 has other DPCD registers specified VESA standard.

1. Does it have all DPCD registers specified VESA standard or part of them?

2. If it have only part of them, could you give me the DPCD register lists on PTN3356?

3. Could you tell me the reset value of their registers?

4. Their reset value are set by internal MCU (MCU read from internal ROM and set to their regisgers) or POR circuit?

Best regards,

M.Kiniwa

[TomasVaverka]

Dear Kiniwa-san,

Yes, the PTN3356 datasheet only describes the contents of PTN3356 specific DPCD registers.

There are a lot of generic DPCD registers which are defined in DisplayPort specification and supported in the PTN3356 firmware.

So if customer is interested in any DPCD register defined in DisplayPort specification, then they can use DPCD tool to read out particular DPCD register from PTN3356 and reference to DisplayPort specification to understand the meaning of settings.

In short, all of DPCD registers (a lot of them) beside PTN3356 specific DPCD registers are defined in the DisplayPort specification, so that customer can reference to the DisplayPort specification to understand them.

Best regards,

Tomas

[masahirokiniwa]

Dear Vaverka-san,

Thank you for you answer.

Does PTN3356 initialize all DPCD register by power-on reset or internal MCU in start-up sequence?

If its generic DPCD registers are not initialized by PTN3356 and their initial values are not fixed, I need to configure them every start-up sequence.

If they are initialized by PTN3356, I can reduce the number of registers that they need to configure.

If they are initialized by PTN3356, could tell me their initialized values?

Best regards,

M.Kiniwa

[TomasVaverka]

Dear Masahiro-san,

Here are the answers to your additional questions:

Does PTN3356 initialize all DPCD register by power-on reset or internal MCU in start-up sequence?

>> Yes.

If its generic DPCD registers are not initialized by PTN3356 and their initial values are not fixed, I need to configure them every start-up sequence.

>> No. Customers do not need to configure any of DPCD register in start-up sequence.

If they are initialized by PTN3356, I can reduce the number of registers that they need to configure.

>> No. The initialized values are required and defined in DisplayPort specification, customers cannot change them.

If they are initialized by PTN3356, could tell me their initialized values?”

>> As said previously, PTN3356 specific DPCD registers are already described in the datasheet. There are a lot of generic DPCD registers (few hundreds) which are defined in the DisplayPort specification, customers can reference to DisplayPort specification to get the values.

Best regards,

Tomas

[masahirokiniwa]

Dear Tomas-san,

Thank you for your answer.

I understand PTN3356 initialize all DPCD register and DP source couldn't change their value.

Generic DPCD registers have many Write/Read registers. I think that the MCU in PTN3356 initialize their value in start-up sequence.

So, I couldn't find their initialize value from DP specification, could you give me their value after initialization?

Best regards,

M.Kiniwa