GS2972 Datasheet, PDF (119/125 Pages) Semtech Corporation – 3G/HD/SD-SDI Serializer with Complete SMPTE Audio & Video Support

4.15 JTAG ID Codeword
The Platform ID for the 297X family is 0Fh.
The part number field of the JTAG ID codeword for the GS2972 is set to 0F01h.
4.16 JTAG Test Operation
When the JTAG/HOST pin is HIGH, the GSPI host interface port is configured for JTAG
test operation.
In this mode the SCLK, SDIN, SDOUT and CS become TCK, TDI, TDO and TMS. In
addition, the TRST pin becomes active.
Boundary scan testing using the JTAG interface is enabled in this mode. When the
JTAG/HOST pin is LOW, the dedicated JTAG interface is used. In this mode the TCK, TDI,
TDO and TMS pins are active. This is the recommended mode for new designs.
4.17 Device Power-Up
Because the GS2972 is designed to operate in a multi-voltage environment, any
power-up sequence is allowed. The Charge Pump, Phase Detector, Core Logic, Serial
Digital Output and I/O Buffers can all be powered up in any order.
4.18 Device Reset
Note: At power-up, the device must be reset to operate correctly.
In order to initialize all internal operating conditions to their default states, hold the
RESET signal LOW for a minimum of t_reset = 1ms after all power supplies are stable.
There are no requirements for power supply sequencing.
When held in reset, all device outputs will be driven to a high-impedance state.
Nominal Level
95% of Nominal Level
Supply Voltage
RESET
Figure 4-35: Reset Pulse
treset
Reset
treset
Reset
GS2972 3G/HD/SD-SDI Serializer with Complete
SMPTE Audio & Video Support
Final Data Sheet Rev. 9
GENDOC-047479 September 2013
www.semtech.com
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