Mode Selection Jumper Settings; Edge Rate Control Jumper Settings - Texas Instruments CDCUN1208LP User Manual

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Configuring the Reference Inputs
The CDCUN1208LP offers two inputs (IN1 and IN2). SMA J4 and J5 are dedicated for IN1 (IN1p and
IN1n) and SMA J7 and J8 are dedicated for IN2 (IN2p and IN2n). Both inputs in the EVM are ac-coupled
as default by using coupling capacitors (C231 and C232 for IN1 and C235 and C236 for IN2). JMP7 and
JMP8 are used to set the input biasing and termination and should be configured according to the Input
Reference section of the EVM schematic.
All inputs have options for 50 Ω to GND. This 50 Ω to GND can be required if the signal generator is used
as input clock source.
Configuring the Control Pins
The device has multiple dedicated pins to control and configure the operation. Setting of these pins is
critical to operate the device correctly.
Mode Selection Pins (MODE): This pin will select the mode of device configuration. The Jumper on the
Header MODE (JP_3_20) is required to set based on
Output Control Pin (OE): This pin can used to enable (HIGH) or disable (LOW) all outputs. For normal
operation, Header CLK_OE (JP_3_23) should be connected to VDD. Connect the Jumper to GND to
disable the outputs. This functionality is only available in pin mode.
Output Signaling Level Selection Pin (OTTP): This pin will select the signaling level of all outputs. The
header OTTP (JP_3_18) is dedicated for this pin. This pin is only available in pin mode.
Output Edge Rate Control Pin (ERC): This pin will select the edge rate for all outputs. The Header
ADD_CS (JP_3_17) is dedicated for this pin. This pin is only available in pin mode.
2
In I C mode, this pin is used to set the host interface address.
IN2 Divider Setting Pin (DIVIDE): This pin will select the divider value of the IN2 input. The Header
DATA_DIV (JP_3_19) is dedicated for this pin. This pin is only available in pin mode.
SCAU050 – May 2012
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Table 1. Mode Selection Jumper Settings
Jumper on MODE Header
GND
VDD
OPEN
Table 2. Mode Selection Jumper Settings
Jumper on OTTP Header
GND
VDD
OPEN
Table 3. Edge Rate Control Jumper Settings
Jumper on OTTP Header
GND
VDD
OPEN
Table 4. Edge Rate Control Jumper Settings
Jumper on DATA_DIV Header
GND
VDD
OPEN
Copyright © 2012, Texas Instruments Incorporated
Table 1.
Mode of Configuration
SPI Mode
I2C Mode
Pin Mode
Output Type
LVDS
I2C Mode
LVCMOS
Output Type
SLOW
Medium
FAST
Output Type
/2
/4
/1
CDCUN1208LP Evaluation Board
Configuring the Board
7