Debug Support
ARM DDI0145B
Copyright © 1998, 1999 ARM Limited. All rights reserved.
5-25
Scan chain 3
Purpose
Allows the ARM9TDMI to control an external boundary scan
chain.
Length
User-defined.
Scan chain 3 is provided so that an optional external boundary scan chain may be
controlled via the ARM9TDMI. Typically this would be used for a scan chain around
the pad ring of a packaged device. The following control signals are provided and are
generated only when scan chain 3 has been selected. These outputs are inactive at all
other times.
DRIVEOUTBS
This is used to switch the scan cells from system mode to test
mode. This signal is asserted whenever either the INTEST,
EXTEST, CLAMP or CLAMPZ instruction is selected.
PCLKBS
This is the update clock, generated in the UPDATE-DR state.
Typically the value scanned into the chain will be transferred to
the cell output on the rising edge of this signal.
ICAPCLKBS, ECAPCLKBS
These are the capture clocks used to sample data into the scan cells
during INTEST and EXTEST respectively. These clocks are
generated in the CAPTURE-DR state.
SHCLK1BS, SHCLK2BS
These are non-overlapping clocks generated in the SHIFT-DR
state that are used to clock the master and slave element of the
scan cells respectively. When the state machine is not in the
SHIFT-DR state, both these clocks are LOW.
In addition to these control outputs,
SDIN
output and
SDOUTBS
input are also
provided. When an external scan chain is in use,
SDOUTBS
should be connected to the
serial data output and
SDIN
should be connected to the serial data input.
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 ...