MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 374

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

MPC555
USER’S MANUAL
Note that dual mapping can operate only for addresses within the FLASH pre-allocat-
ed address (up to 2 Mbytes). This is achieved by programming only six bits for the
base address (11:16); The upper bits are always set as follows:
Where ISB[0:2] represents the bit field in IMMR register that determines the location
of the address map of the MPC555 / MPC556.
With dual mapping, aliasing of address spaces may occur. This happens when the
user maps the dual-mapped region into a region which is also mapped into one of the
four regions available in the memory controller. If the user writes code or data to the
dual-mapped region, care must be taken to avoid overwriting this code or data by nor-
mal accesses of the chip-select region.
There is a match if:
Care must also be taken to avoid overwriting “normal” CSx data with dual-mapped
code or data.
One way to avoid this situation is by disabling the chip-select region and enabling only
the dual-mapped region (DME = 1, but Vx = 0, where x = selected region, 0.3).
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• The memory controller takes control of the external access
• The attributes for the access are taken from one of the base and option registers
• The chip-select region selected is determined by the “CS line select” bit field
/
of the appropriate chip select
(10.8.5 Dual Mapping Base Register
MPC556
illustrates the phenomena.
bus_address[0:16] == {0000000,isb[0:2],0,dmbr_reg_value[1:6]}
bus_addr[0:10]={0000000,isb[0:2],0}
MEMORY CONTROLLER
Rev. 15 October 2000
(DMBR)).
MOTOROLA
Figure
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