Boundary-Scan Test Interface

16.6Test Data Registers

Figure 16-2illustrates the structure of the boundary-scan logic.

Figure 16-2. Boundary-Scan Block Diagram

BSINENCELL

 

 

 

 

Intel®

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

StrongARM®

 

 

 

 

 

 

 

 

 

 

BSINCELL

 

 

 

 

SA-1100

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BSOUTNENCELL

 

 

 

Core Logic

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Device ID Register

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bypass Register

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Instruction Decoder

TDI Instruction Register

BSINCELL

I/O

Cell

BSOUTCELL

BSOUTCELL

TDO

TMS

TCK

nTRST

TAP

Controller

nTDOEN

* StrongARM is a registered trademark of ARM Limited.

A6839-01

16.6.1Bypass 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.

SA-1100 Developer’s Manual

16-5

Page 365
Image 365
Intel SA-1100 manual Test Data Registers, Bypass Register