MPC555
/
MPC556
MEMORY CONTROLLER
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
10-2
chip-select for accessing the boot flash EEPROM. The chip select allows zero to 30
wait states.
is a block diagram of the MPC555 / MPC556 memory controller.
Figure 10-2 Memory Controller Block Diagram
Most memory controller features are common to all four banks. (For features unique
to the CS[0] bank, refer to
10.4 Global (Boot) Chip-Select Operation
.) A full 32-bit
address decode for each memory bank is possible with 17 bits having address mask-
ing. The full 32-bit decode is available, even if all 32 address bits are not sent to the
MPC555 / MPC556 pins.
Each memory bank includes a variable block size of 32 Kbytes, 64 Kbytes and up to
4 Gbytes. Each memory bank can be selected for read-only or read/write operation.
The access to a memory bank can be restricted to certain address type codes for sys-
tem protection. The address type comparison occurs with a mask option as well.
INTERNAL ADDRESSES [0:16, AT[0:2]
ATTRIBUTES
Wait State
Counter
Expired
Load
CS[0:3]
WE/BE[0:3]
OE
Base
Register
Option
Register
Dual Mapping
Base Register (DMBR)
Dual Mapping
Option Register (DMOR)
Base Register 3 (BR3)
Option Register 3 (OR3)
0 (OR0)
1 (OR1)
2 (OR2)
0 (OR0)
1 (OR1)
2 (OR2)
Region Match Logic
General-Purpose
Chip-Select
Machine
(GPCM)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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