CPU

cpu.html

http://www.mentasm.com/~mramiga/c/cpu.html (Amiga Plus Extra No. 5/97, 05/1997)

Format: CPU |CACHE | NOCACHE] [BURST | NOBURST] [DATACACHE | NODATACACHE]

[DATABURST | NODATABURST] [INSTBURST | NOINSTBURST] [INSTCACHE | NOINSTCACHE]

[FASTROM | NOFASTROM] [TRAP | NOTRAP] [COPYBACK | NOCOPYBACK] [EXTERNALCACHE |

NOEXTERNALCACHE] [NOMMUTEST] [CHECK 68010 | 68020 | 68030 | 68040 | 68881 | 68882 |

68851 | MMU | FPU] Template: CACHE/S,BURST/S,NOCACHE/S,NOBURST/S,DATACACHE/S,NODATACACHE/S,

DATABURST/S,NOBURST/S,INSTCACHE/S,NOINSTCACHE/S,INSTBURST/S,NOINSTBURST

/S,COPYBACK/S,NOCOPYBACK/S,EXTERNALCACHE/S,NOEXTERNALCACHE/S,FASTROM/

S,NOFASTROM/S,TRAP/S,NOTRAP/S,NOMMUTEST/S,CHECK/K Location: C:

CPU adjust various options of the microprocessor installed in your Amiga. CPU also shows the proceessor an options that currently enabled.

Many options only work with certian memners 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 and 68040 have two types of cache memory; instruction and data.

If mutually exclusive options are specified, the safest option is used. Availability of the following options depends on the type of microprocessor present.

CACHE

Turns on all caches. NOCACHE

Turns on all caches. BURST

Turns on burst mode for both data and instructions. NOBURST

Turns off burst mode for both data and instructions. DATACACHE

Turns on datacache. NODATACACHE

Turns off datacache. DATABURST

Turns on burst mode for data. NODATABURST

Turns off burst mode for data. INSTCACHE

Turns on instruction cache. NOINSTCACHE

Turns off instruction cache. INSTBURST

Turns on burst mode for instructions. NOINSTBURST

Turns off burst mode for instructions. FASTROM

With a processor having a supported MMU, copies the system ROM into 32-bit RAM, making acces to operating system functions significantly faster. NOFASTROM

Turns off FASTROM. TRAP

This option is for developers only. NOTRAP

This option is for developers only. COPYBACK

Turns on 68040 copyback cache. NOCOPYBACK

turns off 68040 copyback cache. EXTERNALCACHE

Turns on external cache. NOEXTERNALCACHE

Turns off external cache. NOMMUTEST

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

The CHECK option, when given with the keyword (68010, 68020, 68030, 68040, 68881, 68882, 68851, MMU, FPU) checks for the presence of the processor indicated in the keyword.

Example:

CPU NODATACACHE FASTROM

System:  68030  68881 FastROM (INST:  Cache Burst)  (DATA:  Nocache  NoBurst)