M16C62_N Datasheet, PDF (534/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

External Buses
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(2)2-Mbyte ROM and 256-Kbyte SRAM Connection Example
Figure 5.3.8 shows how to connect 2-Mbyte ROM and 256-Kbyte SRAM in microprocessor mode. Locate
both the 2-Mbyte ROM and 256-Kbyte SRAM in the CS0 area that has been extended in memory space
extension mode 2.
Specifically, locate the 2-Mbyte ROM in the area comprised of banks 4 though 7 and the 256-Kbyte
SRAM in the area of bank 0.
CNVss ^CS0
CS1
BYTE CS2
CS3
A0 to A19
RD
WR
D0 to D7
M16C/62
A16 _A1
to _to
A0 _A0
CS0
CS3
S1
S2
RD _OE
WR _W
DQ1 ^D0
to to
DQ8 ^D7
256K bytes SRAM
CS2 _A20
CS1 _A19
A19 _A18
A17 to A0 _{A17 to A0}
CS0
CS3
CE
RD _OE
D0
DQ0 _to
to _D7
DQ7
2M bytes ROM
Figure 5.3.8. 2-Mbyte ROM and 256-Kbyte SRAM Connection Example
_______
_______
_______
Enter the signal decoded from outputs CS0 and CS3 to the 2-Mbyte ROM’s chip enable pin. Connect CS1
_______
and CS2 to the address pins A19 and A20. Connect the M16C’s A19 to the 2-Mbyte ROM’s A18, leaving
the M16C’s A18 unused.
_______
_______
Enter the signal decoded from outputs CS0 and CS3 to the 256-Kbyte SRAM’s chip enable pin.
Access areas in 2-Mbyte ROM and 256-Kbyte SRAM with regard to M16C settings are shown in Table
5.3.2.
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