SLLSFI6A july 2022 – july 2023 TDP1204
PRODUCTION DATA
The TDP1204 supports both linear and limited redriver. Selection between linear and limited can be done from the LINEAR_EN pin in pin-strap mode or through GLOBAL_LINR_EN register in I2C mode.
The limited redriver mode will decouple TDP1204 transmitter's voltage swing, pre-emphasis or de-emphasis, and slew rate from the GPUs transmitter. This allows the GPU to use a lower power TX setting and depends on the TDP1204 transmitter to meet TX compliance requirements. For source applications, it is recommended to configure TDP1204 as a limited redriver. It is not recommended to use limited redriver mode in sink applications.
Unlike limited redriver mode, in linear redriver mode the TDP1204 transmitter's output is not decoupled from the GPU's transmitter. In linear redriver mode, the TDP1204 transmitter's output is a linear function of its input. The linear redriver mode offers transparency to link training which makes it perfect for HDMI 2.1 applications. For HDMI sink applications, it is recommended to configure TDP1204 as a linear redriver.
Table 8-4 lists the requirements that the GPU transmitter must meet if linear redriver mode is used in an HDMI 2.1 source application. Linear redriver mode should only be used for HDMI 2.1 data rates. For HDMI 1.4 and 2.0, the TDP1204 should be configured for limited mode (LINEAR_EN = "0" or "1").
GPU TX Parameter | Min | Max | Units |
---|---|---|---|
Single-ended TX swing for HDMI 2.1 | 400 | 500 | mV |
TX rise/fall time for 3, 6, 8, 10, and 12-Gbps FRL | 16 | mV/ps |
The TDP1204 in pin-strap mode provides the option to dynamically switch between limited and linear based on the HDMI mode of operation. The feature is enabled by setting LINEAR_EN pin = "1".
LINEAR_EN Pin Level | HDMI 1.4, 2.0, or DP | HDMI 2.1 FRL |
---|---|---|
1 | Limited Enabled | Linear Enabled |
F | Linear Enabled Recommended for DP and HDMI sink application. |
Linear Enabled Recommended for DP and HDMI sink application. |
R | Reserved | Reserved |
0 | Limited Enabled. Recommended for HDMI source application |
Limited Enabled Recommended for HDMI source application |