M16C62_N Datasheet, PDF (37/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

Memory Space Expansion Functions
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Memory Space Expansion Features
Here follows the description of the memory space expansion function.
With the processor running in memory expansion mode or in microprocessor mode, the memory space
expansion features provide the means of expanding the accessible space. The memory space expansion
features run in one of the three modes given below.
(1) Normal mode (no expansion)
(2) Memory space expansion mode 1 (to be referred as expansion mode 1)
(3) Memory space expansion mode 2 (to be referred as expansion mode 2)
Use bits 5 and 4 (PM15, PM14) of processor mode register 1 to select a desired mode. The external
memory area the chip select signal indicates is different in each mode so that the accessible memory space
varies. Table 1.8.1 shows how to set individual modes and corresponding accessible memory spaces. For
external memory area the chip select signal indicates, see Table 1.12.1 on page 34.
Table 1.8.1. The way of setting memory space expansion modes and corresponding memory spaces
Expansion mode
Normal mode (no expansion)
Expansion mode 1
Expansion mode 2
How to set PM15 and PM14
0, 0
1, 0
1, 1
Accessible memory space
Up to 1M byte
Up to 1.2M bytes
Up to 4M bytes
Here follows the description of individual modes.
(1) Normal mode (a mode with memory not expanded)
‘Normal mode’ means a mode in which memory is not expanded.
Figure 1.8.1 shows the memory maps and the chip select areas in normal mode.
Normal mode (memory area = 1M bytes for PM15 = 0, PM14 = 0)
Memory expansion mode
Microprocessor mode
0000016
0040016
XXXXX16
0400016
0800016
SFR area
Internal RAM area
Internal area reserved
SFR area
Internal RAMarea
Internal area reserved
CS3 (16K bytes)
CS2 (128K bytes)
2800016
3000016
CS1 (32K bytes)
External area
External area
CS0
D000016
Internal area reserved
YYYYY16
FFFFF16
Internal ROM area
Type No.
M30622M4
M30620M8
M30620MA
Address XXXXX16
00FFF16
02BFF16
02BFF16
M30620MC/EC
M30622M8/E8
M30622MA
M30622MC
M30624MG/FG
02BFF16
013FF16
017FF16
017FF16
053FF16
Address YYYYY16
F800016
F000016
E800016
E000016
F000016
E800016
E000016
C000016
Memory expansion mode: 640K bytes
Microprocessor mode: 832K bytes
Note 1: These memory maps show an instance in which PM13 is set to 0; but in the case of M30624MG/FG, they show an
instance in which PM13 is set to 1.
Note 2: The memory maps in single-chip mode are omitted.
Figure 1.8.1. The memory maps and the chip select areas in normal mode
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