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UNDER ND
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69rlq62d-f714peg4 * Memec (Headquar
ter
s) - Unique
Tec
h,
Insight,
Impact
MAR
VELL CONFIDENTIAL,
UNDER ND
A# 12101050
69r
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ters) - Unique
T
ech, Insight, Impact * UNDER ND
A# 12101050
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OHIBITED
PXA300 Processor and PXA310 Processor
Vol. I: System and Timer Configuration Developers Manual
Doc. No. MV-TBD-00 Rev. A
CONFIDENTIAL
Copyright © 12/13/06 Marvell
Page 62
Document Classification: Proprietary Information
December 13, 2006
Not approved by Document Control. For review only.
•
Completers execute transactions in order for each initiator
3.3
I/O Pins
The PXA300 processor or PXA310 processor memory switch bus has no external IO interface.
3.4
Functional Description
The memory switch bus consists of the following interface modules:
•
Core subsystem interface: The interface between the core subsystem and the bus
•
System bus #1 interface: The interface between system bus #1 and the bus
•
System bus #2 interface: The interface between system bus #2 and the bus
•
Dynamic Memory Controller (DMC) interface: The interface between the DMC and the bus
•
Static Memory Controller (SMC) interface: The interface between the SMC and the bus
•
Internal SRAM interface: The interface between internal SRAM controller and the bus
The interconnections between the memory switch interface modules are shown in .
3.4.1
Priority Control
Each completer interface (internal SRAM, external dynamic memory controller, external static memory
controller) receives transfer requests from three initiators ( core subsystem, system bus #1, and system bus #2).
Within each completer interface, a transaction age-based priority algorithm assures flow control and fairness
based on the age of the transfer. This algorithm may reorder transfers between the three initiator sources despite
the age of the transfer, but it does not reorder transfers within each initiator queue.
Note:
Program the Arbiter Control register to achieve the preferred priority on system bus #1 and
system bus #2. Refer to the ARB_CNTRL_1 and ARB_CNTRL_2 registers (
for more details s on how to prioritize transfers.