SN75DP130 as pass-through mode

TI Lady

Other Parts Discussed in Thread: SN75DP130, SN75DP119, SN75DP118

My question to TI about the SN75DP130 displayport redriver is:

How can I configure the part (via I2C registers and I/O lines) to work in pass-through mode, meaning I don’t want the part to do anything except pass on the signals between the DP source and sink. If link training is happening, I don’t want the part to be involved. Same with the HPD signal.

Note that I’m using the part on the sink side (part of a display controller) in DP only mode (i.e. not DP++ where it reverts to HDMI mode).

Thanks in advance.

over 11 years ago

0 Elias Villegas M. over 11 years ago

TI__Guru* 76130 points

Hello,

Have you looked at the SN75DP118 and SN75DP119? These are probably better suited for you application.

Regards.

0 TI Lady over 11 years ago in reply to Elias Villegas M.

Genius 4025 points

The 118 and 119 do not support 5.4Gbps, which is what we need. Any other recommendations?

0 Elias Villegas M. over 11 years ago

TI__Guru* 76130 points

Hello,

You can configure the DP130 is DP mode only with AUX pass-through by writing a 0 to Bit 2 of the I2C Register 0x04 (LINK TRAINING DISABLE).

Regards.

0 W. over 11 years ago in reply to Elias Villegas M.

Prodigy 60 points

If you disable link training, can't you just use I2C to set the pre-emphasis and VOD such that the 4 DisplayPort links are essentially passed through without any much signal conditioning?

0 Elias Villegas M. over 11 years ago in reply to W.

TI__Guru* 76130 points

Hello,

Yes,

You can use the i2c interface to set the configuration values, for example, if you want to change the EQ level:

Write a zero to bit2 of address 04h.

Write a one to EQ_I2C_ENABLE bit (bit 7 at address 05h), after that, software can program the equalization for each lane (IN[3:0]) to the appropriate value per Table 8 of Datasheet.

Regards.

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SN75DP130 as pass-through mode