Datasheet

TLK2711A

www.ti.com

SLLS908B –JULY 2008–REVISED OCTOBER 2012

TERMINAL FUNCTIONS (Continued)

TERMINAL

NO. I/O DESCRIPTION

NAME

GQE RCP

VDD C5, D5, E5, F5, G5, 1, 9, 23, Digital logic power. Provides power for all digital circuitry and digital I/O buffers.

C6, D6, E6, F6, G6, 38, 48

C7, D7, E7, F7, G7,

VDDA H5 55, 57 Analog power. V

DDA

provides a supply reference for the high-speed analog circuits,

receiver and transmitter.

DETAILED DESCRIPTION

TRANSMIT INTERFACE

The transmitter portion registers valid incoming 16-bit wide data (TXD[0:15]) on the rising edge of the TXCLK.

The data is then 8-bit/10-bit encoded, serialized, and transmitted sequentially over the differential high-speed I/O

channel. The clock multiplier multiplies the reference clock (TXCLK) by a factor of 10 times, creating a bit clock.

This internal bit clock is fed to the parallel-to-serial shift register which transmits data on both the rising and

falling edges of the bit clock, providing a serial data rate that is 20 times the reference clock. Data is transmitted

LSB (TXD0) first.

transmit data bus

The transmit bus interface accepts 16-bit single-ended TTL parallel data at the TXD[0:15] terminals. Data and K-

code control is valid on the rising edge of the TXCLK. The TXCLK is used as the word clock. The data, K-code,

and clock signals must be properly aligned as shown in Figure 2. Detailed timing information can be found in the

electrical characteristics table.

Figure 2. Transmit Timing Waveform

Transmission Latency

The data transmission latency of the TLK2711A is defined as the delay from the initial 16-bit word load to the

serial transmission of bit 0. The transmit latency is fixed once the link is established. However, due to silicon

process variations and implementation variables such as supply voltage and temperature, the exact delay varies

slightly. The minimum transmit latency t

d(Tx latency)

is 34 bit times; the maximum is 38 bit times. Figure 3 illustrates

the timing relationship between the transmit data bus, the TXCLK, and the serial transmit terminals.

Product Folder Links :TLK2711A