M16C62_N Datasheet, PDF (531/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

External Buses
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
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device automatically outputs bank 7 (1, 1, 1) from the CS1, CS2, and CS3 pins each, no matter what bank
number has been set by the bank select bits. When accessing this same area for data, choose bank 7 by
setting the bank select bits first. For the area of bank 7 comprised of addresses C000016 through
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FFFFF16, the device automatically outputs bank 7 (1, 1, 1) from the CS1, CS2, and CS3 pins each, for
either program fetch or data access.
When accessing the area comprised of addresses 0400016 through 3FFFF16, for both program fetch and
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data access, the device outputs the same chip select signal from the CS1, CS2, and CS3 pins each as
output conventionally.
Figure 5.3.5 shows the Data bank register.
Data bank register
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
DBR
Address
000B16
When reset
0016
Bit symbol
Bit name
Description
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to be “0”.
OFS
Offset bit
0: Not offset
1: Offset
BSR
Bank selection bits
b5 b4 b3
0 0 0: Bank 0
0 1 0: Bank 2
1 0 0: Bank 4
1 1 0: Bank 6
b5 b4 b3
0 0 1: Bank 1
0 1 1: Bank 3
1 0 1: Bank 5
1 1 1: Bank 7
RW
Nothing is assigned.
In an attempt to write to these bits, write “0”. The value, if read, turns out to be “0”.
Figure 5.3.5. Data bank register
When alternately accessing areas across the bank boundary, you need to rewrite the bank select bits
each time. In this case, you can avoid this inconvenience by setting the Data bank register’s offset bit (bit
2 at address 0000B16) to 1, because this allows you to access said areas without having to rewrite the
bank select bits.
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