SA-1100 Developer’s Manual 16-5
Boundary-Scan Test Interface
16.6 Test Data Registers
Figure16-2 illustrates the structu r e of th e boundary-scan logic.
Figure 16-2. Boundary-Scan Block Diagram

16.6.1 Bypass Register

Purpose: This is a single-bit register that can be selected as the path between TDI and TDO to
allow the device to be bypassed during boundary-scan testing.
Length: 1 bit
Operating Mode: When the BYPASS instruction is the current instruction in the instruction
register, serial data is transferred from TDI to TDO in the SHIFT-DR state with a delay of one TCK
cycle.
There is no parallel output from the bypass register.
A logic 0 is loaded from the parallel input of the bypass register in the CAPTURE-DR state.
A6839-01
* StrongARM is a registered trademark of ARM Limited.
BSINCELL
BSOUTCELL
BSOUTCELL
BSINENCELL
BSINCELL
BSOUTNENCELL
I/O
Cell
Intel®
StrongARM®
SA-1100
Device ID Register
Bypass Register
Instruction Decoder TDO
TDI
TMS
TCK
nTRST
Instruction Register
nTDOEN
Core Logic
TAP
Controller