M16C62_N Datasheet, PDF (523/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

External Buses
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
5.1 Overview of External Buses
Memory and I/O external expansion can be attained in either the memory expansion mode or the micro-
processor mode. When accessing an external area in either mode, 8-bit data bus width or 16-bit data bus
width can be selected, based on the BYTE pin level. 16-bit width is used to access an internal area,
regardless of the level of the BYTE pin.
Fix the BYTE pin either to “H” or “L” level. 8-bit and 16-bit data bus widths cannot be used together in an
external area.
Addresses (A0 through A19) for accessing a memory space of up to 1M bytes, as well as chip selects
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(CS0 through CS3) which indicate areas resulting from dividing a 1M bytes space into four, can be output
in both the memory expansion mode and microprocessor mode.
Table 5.1.1. Memory space expansion mode and memory spaces
Expansion mode
Normal mode
Expansion mode 1
Expansion mode 2
Accesible memory space
Up to 1M byte
Up to 1.2M byte
Up to 4M byte
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