Downsizing Data Width Function - Altera cyclone V Technical Reference

cv_5v4
2016.10.28
Incrementing Bursts
The interconnect converts all input
burst of the minimum
INCR1
possible for maximum data throughout.
Wrapping Bursts
All bursts are either passed through unconverted as
WRAP
bursts of the output bus. The interconnect converts input
the output data width to a single
Fixed Bursts
All bursts pass through unconverted.
FIXED
Bypass Merge
Bypass merge is accessible through the GPV registers and is only accessible to secure masters. If the
programmable bit
pass through legally without alteration.

Downsizing Data Width Function

The downsizing function reduces the data width of a transaction to match the optimal data width at the
destination. Downsizing does not merge multiple-transaction data narrower than the destination bus if
the transactions are marked as noncacheable.
The downsizing function reduces the data width by the following ratios:
• 2:1
• 4:1
Incrementing Bursts
The interconnect converts
a single
INCR
data bus to multiple
bursts with a size that matches the output data width pass through unconverted.
INCR
The interconnect packs
width whenever possible, using the upsizing function.
Related Information
Upsizing Data Width Function
•
For more information about AXI terms such as
Protocol Specification v1.0, which you can download from the ARM website.
http://infocenter.arm.com
•
For more information about AXI terms such as
Interconnect (NIC-301) Technical Reference Manual, revision r2p3, which you can download from the
ARM Infocenter website.
System Interconnect
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INCR
possible, and packs all
SIZE
INCR
is enabled, the interconnect does not alter any transactions that could
bypass_merge
bursts that fall within the maximum payload size of the output data bus to
INCR
burst. It converts bursts that are greater than the maximum payload size of the output
INCR
bursts.
INCR
bursts with a
INCR
on page 7-20
bursts that complete within a single output data width to an
INCR
bursts, or converted to one or two
WRAP
bursts that have a total payload less than
WRAP
burst.
smaller than the output data width to match the output
SIZE
,
DECERR WRAP
,
DECERR WRAP
Incrementing Bursts
bursts into bursts of the optimal size
INCR
, refer to the AMBA AXI
, and
INCR
, and , refer to the AMBA Network
INCR
7-21
INCR
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