XRT83L34_05 Datasheet, PDF (11/99 Pages) Exar Corporation – QUAD T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR

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XRT83L34
QUAD T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR REV. 1.0.1
SIGNAL NAME
RXRES0
RXRES1
PIN #
108
109
TYPE
I
DESCRIPTION
Receive External Resistor Control Pins - Hardware mode
Receive External Resistor Control Pin 0
Receive External Resistor Control Pin 1
These pins are used to determine the value of the external Receive fixed
resistor according to the following table:
RCLKE
µPTS1
RXRES1 RXRES0
Required Fixed External
RX Resistor
0
0
No External Fixed Resistor
0
1
240Ω
1
0
210Ω
1
1
150Ω
NOTE: These pins are internally pulled “Low” with 50kΩ resistor.
106
I
Receive Clock Edge Select/Microprocessor Type Select Input pin:
The exact function of this input pin depends upon whether the XRT83L34
device has been configured to operate in the HOST or Hardware Mode, as
described below.
Hardware Mode Operation - Receive Clock Edge Select Input pin -
RCLKE:
This input pin permits the user to configure the Receive Section (of each
channel within the XRT83L34 device) to update the data (that is output via
the RPOS_n/RDATA_n and RNEG_n/LCV_n output pins) upon either the ris-
ing edge or falling edge of the RCLK_n output clock signal, as depicted
below.
LOW - Configures all four channels to update the RPOS_n/RDATA_n and
RNEG_n/LCV_n output pins upon rising edge of RCLK_n.
HIGH - Configures all four channels to update the RPOS_n/RDATA_n and
RNEG_n/LCV_n output pins upon the falling edge of RCLK_n.
HOST Mode Operation - Microprocessor Type Select Input pin # 1:
This pin is used to select the microprocessor type. See “Microprocessor
Type Select Input Pins/Receive Clock Edge Select/Transmit Clock
Edge Select Input Pin:” on page 17.
NOTE: This pin is internally pulled "Low" with a 50kΩ resistor.
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