ARM9TDMI Coprocessor Interface
ARM DDI0145B
Copyright © 1998, 1999 ARM Limited. All rights reserved.
4-13
4.5
CDP
CDP signals normally execute in a single cycle. Like all the previous cycles,
InMREQ
is driven LOW to signal when an instruction is entering the decode and then the execute
stage of the pipeline:
•
if the instruction really is to be executed, the
PASS
signal is be driven HIGH
during phase 2 of execute
•
if the coprocessor can execute the instruction immediately it drives
CHSD[1:0]
with LAST
•
if the instruction requires a busy-wait cycle, the coprocessor drives
CHSD[1:0]
with WAIT and then
CHSE[1:0]
with LAST.
Figure 4-5 on page 4-14 shows a CDP which is cancelled due to the previous instruction
causing a data abort. The CDP instruction enters the execute stage of the pipeline and
is signalled to execute by
PASS
. In the following phase
LATECANCEL
is asserted.
This causes the coprocessor to terminate execution of the CDP instruction and for it to
cause no state changes to the coprocessor.
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 ...