Debug Support
5-16
Copyright © 1998, 1999 ARM Limited. All rights reserved.
ARM DDI0145B
BYPASS (1111)
The BYPASS instruction connects a 1-bit shift register (the bypass register) between
TDI
and
TDO
.
When the BYPASS instruction is loaded into the instruction register, all the scan cells
are placed in their normal (system) mode of operation. This instruction has no effect on
the system pins.
In the CAPTURE-DR state, a logic 0 is captured by the bypass register.
In the SHIFT-DR state, test data is shifted into the bypass register via
TDI
and out via
TDO
after a delay of one
TCK
cycle. The first bit shifted out will be a zero.
The bypass register is not affected in the UPDATE-DR state.
Note
All unused instruction codes default to the BYPASS instruction.
CLAMP (0101)
This instruction connects a 1-bit shift register (the bypass register) between
TDI
and
TDO
.
When the CLAMP instruction is loaded into the instruction register, the state of all the
output signals is defined by the values previously loaded into the currently-loaded scan
chain.
Note
This instruction should only be used when scan chain 0 is the currently selected scan
chain.
In the CAPTURE-DR state, a logic 0 is captured by the bypass register.
In the SHIFT-DR state, test data is shifted into the bypass register via
TDI
and out via
TDO
after a delay of one
TCK
cycle. The first bit shifted out will be a zero.
The bypass register is not affected in the UPDATE-DR state.
HIGHZ (0111)
This instruction connects a 1-bit shift register (the bypass register) between
TDI
and
TDO
.
Содержание ARM9TDMI
Страница 1: ...Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ARM9TDMI Technical Reference Manual ...
Страница 6: ...Contents vi Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 12: ...Preface xii Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 16: ...Introduction 1 4 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 22: ...Programmer s Model 2 6 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 36: ...ARM9TDMI Processor Core Memory Interface 3 14 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 54: ...ARM9TDMI Coprocessor Interface 4 18 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 110: ...Test Issues 6 6 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 138: ...ARM9TDMI AC Characteristics 8 20 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 150: ...ARM9TDMI Signal Descriptions A 12 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...
Страница 154: ...Index Index 4 Copyright 1998 1999 ARM Limited All rights reserved ARM DDI0145B ...