PM5380-BI PMC-Sierra, Inc., PM5380-BI Datasheet - Page 403

• Manufacturer Part Number: PM5380-BI
• Description: Network Interface, SATURN User Network Interface (8x155) Telecom Standard Product
• Manufacturer: PMC-Sierra, Inc.

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC- 2010299, Issue 2
13.14 Board Design Recommendations
EXTEST
The external test instruction allows testing of the interconnection to other devices. When the
current instruction is the EXTEST instruction, the boundary scan register is place between
input, TDI and output, TDO. Primary device inputs 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. Primary device outputs can be controlled
by loading patterns shifted in through input TDI into the boundary scan register using the
Update-DR state.
SAMPLE
The sample instruction samples all the device inputs and outputs. For this instruction, the
boundary scan register is placed between TDI and TDO. Primary 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.
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:
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Use a single plane for both digital and analog grounds.
Provide separate +3.3 volt analog 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.
Ferrite beads are not advisable in digital switching circuits because inductive spiking (di/dt
noise) is introduced into the power rail. Using simple RC filtering is 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.
High-frequency decoupling capacitors are recommended for each power 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 power supply transients from coupling into
some internal reference circuitry. See the section on Power Supplies for more details.
S/UNI®-8x155 ASSP Telecom Standard Product Data Sheet
Released
403