[Guide to AmigaDOS 3\CPU] 
 

CPU

Format: CPU [CACHE] [NOCACHE] [BURST] [NOBURST] [DATACACHE] [DATABURST] [NODATACACHE] [NODATABURST] [INSTCACHE] [INSTBURST] [NOINSTCACHE] [NOINSTBURST) [FASTROM] [NOFASTROM] [NOMMUTEST] [CHECK 68010|68020|68030|68040| 68881|68882|68851|MMU|FPU] [TRAP] [NOTRAP] [COPYBACK] [NOCOPYBACK] [EXTERNALCACHE] [NOEXTERNALCACHE] Template: CACHE/S, BURST/S, NOCACHE/S, NOBURST/S, DATACACHE/S, DATABURST/S, NODATACACHE/S, NODATABURST/S, INSTCACHE/S, INSTBURST/S, NOINSTCACHE/S, NOINSTBURST/S, COPYBACWS, NOCOPYBACK/S, EXTERNALCACHE/S, NOEXTERNALCACHE/S, FASTROM/S, NOFASTROM,S, TRAP/S, NOTRAP/S, NOMMUTEST/S, CHECK/K Purpose: To set or clear the CPU caches, check for a particular processor, load the ROM image into fast, 32-bit memory, or set an illegal memory access handler which will output information over the serial port at 9600 baud if a task accesses page zero (lower 256 bytes) or memory above 16M on a 68000 Amiga. Path: C:CPU Specification: CPU allows you to adjust various options of the microprocessor installed in your Amiga. CPU will also show the processor and options that are currently enabled. Many options only work with certain members of the 680X0 processor family. The 68020 has a special type of memory known as instruction cache. When instruction cache is used, instructions are executed more quickly. The 68030 has two types of cache memory: instruction and data. The CPU options, outlined below, specify the types of memory to be used. If mutually exclusive options are specified, the safest option is used. Availability of the options listed below depends on availability of required hardware.

CACHE

Turns on all caches.

NOCACHE

Turns off all caches.

BURST

Turns on burst mode for both data and instructions.

NOBURST

Turns off burst mode for data and instructions.

DATACACHE

Turns on data cache.

NODATACACHE

Turns off data cache.

DATABURST

Turns on burst mode for data.

NODATABURST

Turns off burst mode for data.

INSTCACHE

Turns on instruction cache.

INSTBURST

Turns on burst mode for instruction.

NOINSTCACHE

Turns off instruction cache.

NOINSTBURST

Turns off burst mode for instructions.

FASTROM

If supported by the MMU, copies data from ROM into 32-bit RAM, making access to this data significantly faster. CPU then writeprotects the RAM area so that the data cannot be changed.

NOFASTROM

Turns off FASTROM.

NOMMUTEST

Allows the MMU settings to be changed without checking to see if MMU is currently in use.

TRAP

Developer-specific.

NOTRAP

Developer-specific.

COPYBACK

Turns on cache copyback.

NOCOPYBACK

Turns off cache copyback.

EXTERNALCACHE

Turns on external cache.

NOEXTERNALCACHE

Turns off external cache. The CHECK option, when given with a keyword (68010, 68020, 68030, 68040, 68881, 68882, or 68851, MMU, FPU) checks for the presence of the keyword. Examples: 1> CPU System: 68030 68881 (INST: Cache Burst) (DATA: Cache NoBurst) 1> CPU NoDataCache FastROM System: 68030 68881 FastROM (INST: Cache Burst) DATA: NoCache NoBurst) 1> CPU NoBurst DataCache NoInstCache System: 68030 68881 (INST: NoCache NoBurst) (DATA: Cache NoBurst)


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