CS61581-IP View Datasheet(PDF) - Cirrus Logic

Part Name

Description

MFG CO.

CS61581-IP

T1/E1 Universal Line Interface

Cirrus Logic 

CS61581

SDI - Serial Data Input, Pin 24 (Host Mode).

Data input to the on-chip register is sampled on the rising edge of SCLK.

SDO - Serial Data Output, Pin 25 (Host Mode).

Status and control information are output from the on-chip register on SDO. If CLKE is high, SDO is

valid on the rising edge of SCLK. If CLKE is low, SDO is valid on the falling edge of SCLK. SDO goes

to a high-impedance state when the serial port is being written to, or after bit D7 is output or CS goes

high (whichever occurs first).

CS - Chip Select, Pin 26 (Host Mode).

The serial interface is accessible when CS transitions from high to low.

SCLK - Serial Clock Input, Pin 27 (Host Mode).

SCLK is used to write or read data bits to or from the serial port registers.

CLKE - Clock Edge, Pin 28 (Host Mode).

Setting CLKE to logic 1 causes RPOS and RNEG (RDATA) to be valid on the falling edge of RCLK, and

SDO to be valid on the rising edge of SCLK. Conversely, setting CLKE to logic 0 causes RPOS and

RNEG (RDATA) to be valid on the rising edge of RCLK and SDO to be valid on the falling edge of

SCLK.

6.6 Data Input/Output

TCLK - Transmit Clock Input, Pin 2.

The 1.544 MHz (2.048 MHz) transmit clock is input on this pin. TPOS and TNEG or TDATA are

sampled on the falling edge of TCLK.

TPOS/TNEG - Transmit Positive Pulse, Transmit Negative Pulse, Pins 3 and 4.

Data input to TPOS and TNEG is sampled on the falling edge of TCLK and transmitted onto the line at

TTIP and TRING. An input on TPOS results in transmission of a positive pulse; an input on TNEG

results in transmission of a negative pulse. If TNEG is held high for 16 TCLK cycles, the CS61581

reconfigures for unipolar (single pin NRZ) data at pins 3 and 7, TDATA and RDATA. If TNEG goes low

the CS61581 switches back to two-pin bipolar data input format. The device should be reset when

changing between unipolar and bipolar mode.

TDATA - Transmit Data, Pin 3.

When pin 4, TNEG/UBS, is held high, pin 3 becomes TDATA, a single-line NRZ (unipolar) data input

sampled on the falling edge of TCLK.

UBS - Unipolar / Bipolar Select, Pin 4.

When UBS is held high for 16 consecutive TCLK cycles (15 consecutive bipolar violations) the CS61581

reconfigures for unipolar (single-line NRZ) data input / output format. Pin 3 becomes TDATA, pin 7

becomes RDATA, and pin 6 becomes BPV.

RCLK - Recovered Clock Output, Pin 8.

RCLK outputs the clock recovered from the input signal at RTIP and RRING. In a Loss of Signal state

RCLK reverts to the MCLK frequency, or retains the frequency prior to the LOS state, depending on the

clocks provided. See the LOS pin description.

RNEG/RPOS - Receive Negative Pulse, Receive Positive Pulse, Pins 6 and 7.

Recovered data output on RPOS and RNEG is stable and valid on the rising edge of RCLK in Hardware

Mode. In Host Mode, CLKE determines the edge of RCLK on which RPOS and RNEG are valid. A

positive pulse on RTIP with respect to RRING generates a logic 1 on RPOS; a positive pulse on RRING

with respect to RTIP generates a logic 1 on RNEG.

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DS211PP8

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