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PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
243
The boundary scan architecture consists of a TAP controller, an instruction
register with instruction decode, a bypass register, a device identification register
and a boundary scan register. The TAP controller interprets the TMS input and
generates control signals to load the instruction and data registers. The
instruction register with instruction decode block is used to select the test to be
executed and/or the register to be accessed. The bypass register offers a single-
bit delay from primary input, TDI to primary output, TDO. The device
identification register contains the device identification code.
The boundary scan register allows testing of board inter-connectivity. The
boundary scan register consists of a shift register place in series with device
inputs and outputs. Using the boundary scan register, all inputs can be sampled
and shifted out on primary output, TDO. In addition, patterns can be shifted in
on primary input, TDI and forced onto all outputs.
TAP Controller
The TAP controller is a synchronous finite state machine clocked by the rising
edge of primary input, TCK. All state transitions are controlled using primary
input, TMS. A description of the finite state machine follows: