AN2667 Freescale Semiconductor / Motorola, AN2667 Datasheet - Page 7

• Manufacturer Part Number: AN2667
• Description: Multi-Controller Hardware Development for the MPC5xx Family
• Manufacturer: Freescale Semiconductor / Motorola

3.4
In a single controller system the microcontroller is configured from reset using the Reset
Configuration Word(RCW). Since the system has a common data bus, it is necessary to
program RESET configuration in different ways in a multi-controller system. All MPC5xx
devices in the multi-controller system have to be configured from reset using the RCW,
however these words have to be taken from different places as each device will be
configured differently.
There are three places the RCW can be selected from. Those being:
E.g. One possibility is to program one device with the external RCW (RSTCONF=0) and
the other with the internal RCW (from internal flash memory, RSTCONF=1).
MOTOROLA
• Slave Mode (RCPU Core Is Active)
• Peripheral Mode (RCPU Core Is Shut Down)
EMCR[SLVM] = 0. When in master mode no external master can access the
MPC5XX internal address space.
To select Slave mode EMCR[PRPM] = 0 & EMCR[SLVM] = 1
Application code can be executed in this mode. This mode also allows the slave
access to the internal address space of the master..
This mode is only valid if peripheral mode is not selected i.e. peripheral mode will
override slave selection.
For the devices that are configured to operate in slave mode, the MLRC[0:1] field should be
set to “01” or “11” in order to operate the pin IRQ3/KR/RETRY/SGPIOC3 as RETRY.
MLRC[0:1] bits are located in the SIUMCR register of the USIU and their function is to
determine the operation of pin multiplexing.
If the EMCR[PRPM] bit is set, the core of the device is shut off and an
alternative master on the external bus can access any internal module. At least
one MPC5xx in the system must have this bit cleared as there must be at least
one master.
This mode is selectable from reset by setting D16(EMCR[PRPM] ) of the Reset
Configuration Word(RCW). In this mode the peripherals are accessed in the
same manner as an external memory.Also in this mode there can be no access
to the master as the core is shut down. This mode is also selectable by
EMCR[PRPM] = 1.
RESET Configuration
– Data bus
– Internal Flash
– Default(all 0s)
– Master
– Slave
Multi-Controller Hardware Development for the MPC5xx Family
Freescale Semiconductor, Inc.
For More Information On This Product,
= MPC563
= MPC561
Go to: www.freescale.com
RCW from internal flash
Data bus
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