CHAPTER 4 MEMORY MANAGEMENT SYSTEM
User’s Manual U14272EJ3V0UM
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Table 4-1. V
R
4181 Physical Address Space
Physical address
Space
Capacity (bytes)
0xFFFF FFFF to 0x2000 0000
Mirror image of 0x1FFF FFFF to 0x0000 0000
3.5 G
0x1FFF FFFF to 0x1800 0000
ROM space
128 M
0x17FF FFFF to 0x1400 0000
External system bus I/O space (ISA I/O)
64 M
0x13FF FFFF to 0x1000 0000
External system bus memory space (ISA memory)
64 M
0x0FFF FFFF to 0x0D00 0000
Space reserved for future use
48 M
0x0CFF FFFF to 0x0C00 0000
Internal ISA I/O space 1
16 M
0x0BFF FFFF to 0x0B00 0000
Internal ISA I/O space 2
16 M
0x0AFF FFFF to 0x0A00 0000
MBA bus I/O space
16 M
0x09FF FFFF to 0x0400 0000
Space reserved for future use
96 M
0x03FF FFFF to 0x0000 0000
DRAM (SDRAM) space
64 M
4.2.1 ROM space
The ROM space mapping differs depending on the capacity of the ROM being used. The ROM capacity is set via
the ROMs(1:0) bits in the BCUCNTREG1 register.
The physical addresses of the ROM space are listed below.
Table 4-2. ROM Address Map
Physical address
When using 32-Mbit ROM
When using 64-Mbit ROM
0x1FFF FFFF to 0x1FC0 0000
Bank 3 (ROMCS3#)
Bank 3 (ROMCS3#)
0x1FBF FFFF to 0x1F80 0000
Bank 2 (ROMCS2#)
0x1F7F FFFF to 0x1F40 0000
Bank 1 (ROMCS1#)
Bank 2 (ROMCS2#)
0x1F3F FFFF to 0x1F00 0000
Bank 0 (ROMCS0#)
0x1EFF FFFF to 0x1E80 0000
Reserved for future use
Bank 1 (ROMCS1#)
0x1E7F FFFF to 0x1E00 0000
Bank 0 (ROMCS0#)
4.2.2 External system bus space
The following two types of system bus space are available.
• External system bus I/O space
This corresponds to the ISA’s I/O space.
• External system bus memory space
This corresponds to the ISA’s memory space.