AT32UC3C2512C Automotive Atmel Corporation, AT32UC3C2512C Automotive Datasheet - Page 284

• Manufacturer Part Number: AT32UC3C2512C Automotive
• Manufacturer: Atmel Corporation

16. HSB Bus Matrix (HMATRIXB)
16.1
16.2
16.3
16.3.1
16.4
16.4.1
9166C–AVR-08/11
Features
Overview
Product Dependencies
Functional Description
Clocks
Special Bus Granting Mechanism
Rev: 1.3.0.3
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The Bus Matrix implements a multi-layer bus structure, that enables parallel access paths
between multiple High Speed Bus (HSB) masters and slaves in a system, thus increasing the
overall bandwidth. The Bus Matrix interconnects up to 16 HSB Masters to up to 16 HSB Slaves.
The normal latency to connect a master to a slave is one cycle except for the default master of
the accessed slave which is connected directly (zero cycle latency). The Bus Matrix provides 16
Special Function Registers (SFR) that allow the Bus Matrix to support application specific
features.
In order to configure this module by accessing the user registers, other parts of the system must
be configured correctly, as described below.
The clock for the HMATRIX bus interface (CLK_HMATRIX) is generated by the Power Manager.
This clock is enabled at reset, and can be disabled in the Power Manager.
The Bus Matrix provides some speculative bus granting techniques in order to anticipate access
requests from some masters. This mechanism reduces latency at first access of a burst or single
transfer. This bus granting mechanism sets a different default master for every slave.
At the end of the current access, if no other request is pending, the slave remains connected to
its associated default master. A slave can be associated with three kinds of default masters: no
default master, last access master, and fixed default master.
User Interface on peripheral bus
Configurable number of masters (up to 16)
Configurable number of slaves (up to 16)
One decoder for each master
Programmable arbitration for each slave
Programmable default master for each slave
One cycle latency for the first access of a burst
Zero cycle latency for default master
One special function register for each slave (not dedicated)
– Round-Robin
– Fixed priority
– No default master
– Last accessed default master
– Fixed default master
AT32UC3C
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