Motorola MCF5281 用户手册

2-20

MOTOROLA

 

23–20 RAM0SIZ RAM bank 0 size. The first RAM bank can be used for either SRAM or Flash. The first encodings 

shown are used to indicate the size of a RAM bank, and the second set of encodings indicate the 
size for a Flash bank. On the MCF5282, RAM0 is associated with the on-chip Flash, so these bits 
use the Flash encodings.

RAM size encodings:
0x0–0x3  No RAM.
0100 

 4KB RAM.

0101 

 8KB RAM.

0110  

16KB 

RAM.

0111  

32KB 

RAM.

1000  

64KB 

RAM.

1001  

128KB 

RAM.

0xA–0xF  Reserved.

Flash size encodings:
0x0–0x7  No Flash.
1000  64KB Flash.
1001  128KB Flash.
1010  256KB Flash.
1011  512KB Flash. (This is the value used for MCF5282)
0xC–0xF  Reserved.

19–16 ROM0SIZ ROM bank 0 size.

0x0–0x3   No ROM. (This is the value used for MCF5282)
0100 

 4KB ROM.

0101 

 8KB ROM.

0110  

16KB 

ROM.

0111  

32KB 

ROM.

1000  

64KB 

ROM.

1001  

128KB 

ROM.

0xA–0xF  Reserved.

15–14

BUSW

Encoded bus data width.
00  32-bit data bus (only configuration currently in use).

13–12

DCA

Data cache associativity.
00 Four-way.
01 Direct mapped. (This is the value used for MCF5282)

11–8

DCSIZ

Data cache size.
0000  No data cache. (This is the value used for MCF5282)
0001  512B data cache.
0010  1KB data cache.
0011  2KB data cache.
0100  4KB data cache.
0101  8KB data cache.
0110  16KB data cache.
0111  32KB data cache.
1000  64KB data cache.
0x9–0xF  Reserved.