MC68EC040RC25 Freescale Semiconductor, MC68EC040RC25 Datasheet - Page 50

• Manufacturer Part Number: MC68EC040RC25
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC040RC25

• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 25MHz
• Instruction Set Architecture: RISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 179
• Package Type: PGA
• Lead Free Status / Rohs Status: Supplier Unconfirmed

SECTION 3
MEMORY MANAGEMENT UNIT
(EXCEPT MC68EC040 AND MC68EC040V)
The M68040 supports a demand-paged virtual memory environment. Demand means that
programs request memory accesses through logical addresses, and paged means that
memory is divided into blocks of equal size, called page frames. Each page frame is
divided into pages of the same size. The operating system assigns pages to page frames
as they are required to meet the needs of the program.
The M68040 memory management includes the following features:
The MMUs completely overlap address translation time with other processing activities
when the translation is resident in one of the ATCs. ATC accesses operate in parallel with
MOTOROLA
• Independent Instruction and Data Memory Management Units (MMUs)
• 32-Bit Logical Address Translation to 32-Bit Physical Address
• User-Defined 2-Bit Physical Address Extension
• Addresses Translated in Parallel with Indexing into Data or Instruction Cache
• 64-Entry Four-Way Set-Associative Address Translation Cache (ATC) for Each MMU
• Global Bit Allowing Flushes of All Nonglobal Entries from ATCs
• Selectable 4K or 8K Page Size
• Separate Supervisor and User Translation tables
• Two Independent Blocks for Each MMU Can Be Defined as Transparent
• Three-Level Translation Tables with Optional Indirection
• Supervisor and Write Protections
• History Bits Automatically Maintained in Descriptors
• External Translation Disable Input Signal (MDIS) for Emulator Support
• Caching Mode Selected on Page Basis
(128 Total Entries)
(Untranslated)
This section does not apply to the MC68EC040 and
MC68EC040V. Refer to Appendix B MC68EC040 for details.
All references to M68040 in this section only, refer to the
MC68040, MC68040V, and MC68LC040.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
M68040 USER'S MANUAL
NOTE
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