Overview
1.3.2 Crossbar switch (XBAR)
The XBAR multi-port crossbar switch supports simultaneous connections between four master ports and three slave ports. The
crossbar supports a 32-bit address bus width and a 64-bit data bus width.
The crossbar allows four concurrent transactions to occur from any master port to any slave port, although one of those transfers
must be an instruction fetch from internal flash memory. If a slave port is simultaneously requested by more than one master
port, arbitration logic selects the higher priority master and grants it ownership of the slave port. All other masters requesting
that slave port are stalled until the higher priority master completes its transactions.
The crossbar provides the following features:
• Four masters and three slaves supported per each replicated crossbar
— Masters allocation for each crossbar: e200z4d core with two independent bus interface units (BIU) for I and D
access (two masters), one DMA, one FlexRay
— Slaves allocation for each crossbar: a redundant flash-memory controller with two slave ports to guarantee
maximum flexibility to handle Instruction and Data array, one redundant SRAM controller with one slave port
each and one redundant peripheral bus bridge
• 32-bit address bus and 64-bit data bus
• Programmable arbitration priority
— Requesting masters can be treated with equal priority and are granted access to a slave port in round-robin method,
based upon the ID of the last master to be granted access or a priority order can be assigned by software at
application run time
• Temporary dynamic priority elevation of masters
The XBAR is replicated for each processor.
1.3.3 Memory Protection Unit (MPU)
The Memory Protection Unit splits the physical memory into 16 different regions. Each master (DMA, FlexRay, CPU) can be
assigned different access rights to each region.
• 16-region MPU with concurrent checks against each master access
• 32-byte granularity for protected address region
The memory protection unit is replicated for each processor.
1.3.4 Enhanced Direct Memory Access (eDMA)
The enhanced direct memory access (eDMA) controller is a second-generation module capable of performing complex data
movements via 16 programmable channels, with minimal intervention from the host processor. The hardware microarchitecture
includes a DMA engine which performs source and destination address calculations, and the actual data movement operations,
along with an SRAM-based memory containing the transfer control descriptors (TCD) for the channels. This implementation
is used to minimize the overall block size.
The eDMA module provides the following features:
• 16 channels supporting 8-, 16-, and 32-bit value single or block transfers
• Support variable sized queues and circular buffered queue
• Source and destination address registers independently configured to post-increment or stay constant
• Support major and minor loop offset
• Support minor and major loop done signals
• DMA task initiated either by hardware requestor or by software
• Each DMA task can optionally generate an interrupt at completion and retirement of the task
• Signal to indicate closure of last minor loop
MPC5643L Microcontroller Data Sheet, Rev. 3
8
Preliminary—Subject to Change Without Notice
Freescale Semiconductor