Functional Description
2-22
Copyright © 2002, 2003 ARM Limited. All rights reserved.
ARM DDI 0275D
Synchronous HCLK and CLK
When
HCLK
and
CLK
are synchronous,
HCLKEN
is used to control the generation
of
HCLK
, which is derived from
CLK
. This means that the
HCLK
rising edge always
corresponds to a
CLK
rising edge. Therefore, the read transfer does not require any
synchronization logic (the
SBYPASS
signal is HIGH).
A software read cycle with
CLK
and
HCLK
synchronous is shown in Figure 2-9 on
page 2-21. The pipelined nature of the ETB11 data means that data takes more than a
single cycle to perform a read (and write) operation. Wait states are inserted until the
read cycle is completed.
Figure 2-10 Software read cycle with synchronous CLK and HCLK
2.11.2
Write transfer
Two types of write transfer are described:
•
•
Asynchronous HCLK and CLK
The relationship between
HReq
and
CReq
, and
CAck
and
HAck
is the same as it is for
a read transfer.
Summary of Contents for ETB11
Page 6: ...List of Tables vi Copyright 2002 2003 ARM Limited All rights reserved ARM DDI 0275D ...
Page 8: ...List of Figures viii Copyright 2002 2003 ARM Limited All rights reserved ARM DDI 0275D ...
Page 46: ...Functional Description 2 26 Copyright 2002 2003 ARM Limited All rights reserved ARM DDI 0275D ...
Page 70: ...Signal Descriptions A 6 Copyright 2002 2003 ARM Limited All rights reserved ARM DDI 0275D ...
Page 78: ...Glossary Glossary 4 Copyright 2002 2003 ARM Limited All rights reserved ARM DDI 0275D ...