12. Memory Space Expansion Function; Introduction; Registers - Renesas M16C/64A Series User Manual

M16C/64A Group

12. Memory Space Expansion Function

12.1

Introduction

The following describes the memory space expansion function. In memory expansion or microprocessor
mode, the memory space expansion function allows the access space to be expanded. Table 12.1 lists
Memory Space Expansion Function Specifications. In this chapter, the external area accessed by the CSi
(i = 0 to 3) signal is referred to as the CSi area.
Table 12.1 Memory Space Expansion Function Specifications
Item
1-MB mode
4-MB mode
i = 0 to 3
12.2

Registers

Table 12.2 lists registers related to the memory expansion function. Refer to 10. "Processor Mode" for the
PM1 register.
Table 12.2 Registers
Address
0005h Processor Mode Register 1
000Bh Data Bank Register
R01UH0136EJ0210 Rev.2.10
Jul 31, 2012
•
Memory space 1 MB (no expansion)
Specify the external area ( CSi area) accessed by the CSi signal.
•
•
Memory space 4 MB
•
Select bank numbers to access to data.
•
Allows the accessed address to be offset by 40000h
The CSi pin function differs depending on the area to be accessed.
•
Register
12. Memory Space Expansion Function
Specification
Symbol
PM1
DBR
Reset Value
0000 1000b
00h
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