PMC-Sierra, Inc.

S/UNI-QUAD

DATASHEET

PM5349 S/UNI-QUAD

PMC-971239

ISSUE 6

SATURN USER NETWORK INTERFACE (155-QUAD)

 

 

 

device inputs and outputs can be sampled by loading the boundary scan register using the Capture-DR state. The sampled values can then be viewed by shifting the boundary scan register using the Shift-DR state.

IDCODE

The identification instruction is used to connect the identification register between TDI and TDO. The device's identification code can then be shifted out using the Shift-DR state.

STCTEST

The single transport chain instruction is used to test out the TAP controller and the boundary scan register during production test. When this instruction is the current instruction, the boundary scan register is connected between TDI and TDO. During the Capture-DR state, the device identification code is loaded into the boundary scan register. The code can then be shifted out output, TDO using the Shift-DR state.

13.7 Board Design Recommendations

The noise environment and signal integrity are often the limiting factors in system performance. Therefore, the following board design guidelines must be followed in order to ensure proper operation:

1.Use a single plane for both digital and analog grounds.

2.Provide separate +3.3 volt analog transmit, +3.3 volt analog receive, and +3.3 volt digital supplies, but otherwise connect the supply voltages together at one point close to the connector where +3.3 volts is brought to the card.

3.Ferrite beads are not advisable in digital switching circuits because inductive spiking (di/dt noise) is introduced into the power rail. Simple RC filtering is probably the best approach provided care is taken to ensure the IR drop in the resistance does not lower the supply voltage below the recommended operating voltage.

4.Separate high-frequency decoupling capacitors are recommended for each analog power (TAVD, RAVD and QAVD) pin as close to the package pin as possible. Separate decoupling is required to prevent the transmitter from coupling noise into the receiver and to prevent transients from coupling into some reference circuitry.

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

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PMC-Sierra PM5349 manual Idcode, Stctest, Board Design Recommendations