MMC2107 Datasheet, PDF (522/618 Pages) –

Freescale Semiconductor, Inc.
Chip Select Module
20.3 Features
Features of the chip select module include:
• Reduced system complexity — No external glue logic required for
typical systems if chip selects are used.
• Four programmable asynchronous active-low chip selects
(CS[3:0]) — Chip selects can be independently programmed with
various features.
• Control for external boot device — CS0 can be enabled at reset to
select an external boot device.
• Fixed base addresses with 8-Mbyte block sizes
• Support for emulating internal memory space — When the EMINT
bit is set in the chip configuration register (CCR), CS1 matches
only addresses in the internal memory space.
• Support for 16-bit and 32-bit external devices — The external port
size can be programmed to be 16 or 32 bits.
• Programmable write protection — Each chip select address range
can be designated for read access only.
• Programmable access protection — Each chip select address
range can be designated for supervisor access only.
• Write-enable selection — The enable byte pins (EB[3:0]) can be
configured as byte enables (assert on both external read and write
accesses) or write enables (only assert on external write
accesses).
• Bus cycle termination — This option allows the chip select logic to
terminate the bus cycle.
• Programmable wait states — To interface with various devices, up
to seven wait states can be programmed before the access is
terminated.
• Programmable extra wait state for write accesses — One wait
state can be added to write accesses to allow writing to memories
that require additional data setup time.
Technical Data
522
Chip Select Module
For More Information On This Product,
Go to: www.freescale.com
MMC2107 – Rev. 2.0
MOTOROLA