Evaluation Board Inputs and Outputs
13
SNAU200 – September 2016
Copyright © 2016, Texas Instruments Incorporated
LMK04208 User’s Guide
Table 5. Description of Evaluation Board Inputs and Outputs (continued)
CONNECTOR NAME
SIGNAL TYPE,
INPUT/OUTPUT
DESCRIPTION
Test point:
Holdover_TP
CMOS,
Input/Output
Programmable status output pin. By default, set to output the digital lock detect
status signal for PLL2.
In the default TICS Pro modes, LED D4 will illuminate red when Holdover mode is
engaged (output is high) and turn off when holdover is disengaged (output is low).
Status_Holdover pin
27
The status output signal for the Status_Holdover pin can be selected on the
User
Controls
page via the HOLDOVER_MUX and HOLDOVER_TYPE controls.
For debugging purposes, it is suggested to set LD_MUX/Status_LD to output
PLL1 DLD and HOLDOVER_MUX/Status_Holdover to output PLL2 DLD
individually. In holdover mode PLL1 DLD will normally be low but may flicker
high momentarily.
Test points:
CLKin0_SEL_TP
CLKin1_SEL_TP
CMOS,
Input/Output
Programmable status I/O pins. By default, set as input pins for controlling input
clock switching of CLKin0 and CLKin1 if Pin Select mode is enabled by
CLKin_Select_MODE.
These inputs will not be functional because CLKin_SEL_MODE is set to 0 (CLKin0
Manual) by default in the
User Controls
page in TICS Pro. To enable input clock
switching, CLKin_SEL_MODE must be 3 and Status_CLKinX_TYPE must be 0 to 2
(pin enabled as an input).
Input Clock Switching – Pin Select Mode
When CLKin_Select_MODE is 3 and CLKin_Sel_INV = 0, the Status_CLKinX pins
select which clock input is active as follows:
Status_CLKin1
Status_CLKin0
Active Clock
0
0
CLKin0
0
1
CLKin1
1
0
Reserved
1
1
Holdover
Test point:
SYNC_TP
CMOS,
Input/Output
Programmable status I/O pin. By default, set as an input pin for synchronizing the
clock outputs with a fixed and known phase relationship between each clock output
selected for SYNC. A SYNC event also causes the digital delay values to take
effect.
A physical SYNC pin transition may be emulated by toggling the SYNC_POL_INV
bit.
Populated:
SYNC
SYNC pin can hold outputs in a low state, depending on system configuration
(NO_SYNC_CLKoutX bits). SYNC_POL_INV adjusts for active low or active high
control.
A SYNC event can also be programmed by toggling the SYNC_POL_INV bit in the
User Controls
page in TICS Pro.
