TFP501

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SLDS127C

– JULY 2001 – REVISED JULY 2011

Three TMDS channels are used to receive RGB pixel data during active display time, DE = High. These same

three channels are also used to receive HSYNC, VSYNC, CTL3, and two user definable control signals,

CTL[2:1], during inactive display or blanking interval (DE = Low). The following table maps the received input

data to the appropriate TMDS input channel in a DVI-compliant system.

RECEIVED PIXEL DATA

OUTPUT PINS

INPUT CHANNEL

ACTIVE DISPLAY DE = HIGH

(VALID FOR DE = HIGH)

Red[7:0]

Channel

– 2 (Rx2 ±)

QE[23:16] QO[23:16]

Green[7:0]

Channel

– 1 (Rx1 ±)

QE[15:8] QO[15:8]

Blue[7:0]

Channel

– 0 (Rx0 ±)

QE[7:0] QO[7:0]

RECEIVED CONTROL DATA

OUTPUT PINS

TMDS INPUT CHANNEL

BLANKING DE = LOW

(VALID FOR DE = LOW)

Channel

– 2 (Rx2 ±)

CTL2

Channel

– 1 (Rx1 ±)

CTL1

HSYNC, VSYNC

Channel

– 0 (Rx0 ±)

HSYNC, VSYNC

(1)

Some TMDS transmitters transmit a CTL0 signal. The TFP501 decodes and transfers CTL[32:1] and ignores CTL0 characters. CTL3 is

used internally to enabl HDCP decryption. CTL3 and CTL0 are not available as a TFP4501 outputs.

The TFP501 discriminates between valid pixel TMDS characters and control TMDS characters to determine the

state of active display versus blanking, i.e., state of DE.

HIG-BANDWIDTH DIGITAL CONTENT PROTECTION (HDCP) OVERVIEW

TI's HDCP transmitters and receivers use up to three cipher engines to protect information that may be externally

accessible to the user.

The downstream encryption described in the specification high-bandwidth digital content protection system

Revision 1.0 is used to protect video data passing from the HDCP transmitter to the HDCP receiver via a DVI

link. The HDCP transmitter encrypts video data and the receiver decrypts the data as shown inFigure 13.

The HDCP keys must also be protected from access. TI has chosen to avoid the inconvenience and possible

circuit board damage from using epoxy or other barriers between the EEPROM and DVI receiver. An encryption

scheme is used to protect the HDCP device key values passing from an off-chip EEPROM to the HDCP receiver

EEPROM, decrypted, and used to enable HDCP functionality. TI's HDCP solution provides real advantages with

respect to lower systems level cost, ease of implementation, high performance, and exceptional security.

Copyright

© 2001–2011, Texas Instruments Incorporated

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