M38002M4 Datasheet, PDF (98/173 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.4 Processor mode
2.4.3 Processor mode application examples
(1) Application example of memory expansion in the case where the ONW (One-Wait)
function is not used
Outline : The external memory is accessed in the microprocessor mode.
At f(XIN) = 8 MHz, an available RAM is given by the following :
• OE access time : ta (OE) ≤ 50 ns
• Setup time for writing data : tsu (D) ≤ 65 ns
For example, the M5M5256BP-10 whose address access is 100 ns is available.
Figure 2.4.3 shows an expansion example of a 32K byte ROM and a 32K byte RAM.
3800 group
CNVSS
AD15
ONW
M5M27C256AK-10 M5M5256BP-10
2 P30 , P31
CE
8 P4
AD14
AD0
74F04
15
A0–A14
EPROM
S
A0–A14
SRAM
8 P5
8 P6
2 P7
DB0
DB7
RD
WR
8
D0–D7
OE
8MHz VCC = 5.0V ± 10 %
DQ1–DQ8
OE W
Memory map
000016 _{External RAM area}
(M5M5256BP)
000816 _{SFR area}
004016 _{Internal RAM area}
044016 _{External RAM area}
(M5M5256BP)
800016
External ROM area
(M5M27C256AK)
FFFF16
Fig. 2.4.3 Expansion example of ROM and RAM
2-50
3800 GROUP USER’S MANUAL