MITSUBISHI MICROCOMPUTERS
7470/7471 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
Table 2. Pin function in EPROM mode
M37470E4/E8, M37471E4/E8
EPROM MODE
The M37470E4/E8, M37471E4/E8 feature an EPROM mode in ad-
dition to its normal modes. When the RESET signal level is low
(“L”), the chip automatically enters the EPROM mode. Table 2 lists
the correspondence between pins and Figure 30 to 32 give the pin
connection in the EPROM mode. When in the EPROM mode,
ports P0, P11–P17, P20–P23, P3, P40, P41, VREF are used for the
PROM (equivalent to the M5L27256). When in this mode, the built-
in PROM can be written to or read from using these pins in the
same way as with the M5L27256. The oscillator should be con-
nected to the XIN and XOUT pins, or external clock should be
connected to the XIN pin.
M5L27256
VCC
VCC
VPP
VSS
VCC
P33
VSS
VPP
VSS
Ports P11–P17, P20–P23,
P30, P31, P40, P41
Address input
A0–A14
Data I/O
CE
Port P0
VREF
P32
D0–D7
CE
OE
OE
1
42
41
40
P52
P53
2
3
4
5
6
7
8
9
A10
A9
P07
D7
D6
P17/SRDY
P16/CLK
P15/SOUT
P14/SIN
P06
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
A8
P05
D5
D4
P04
A7
A6
A5
A4
P03
T1
T0
P13/
P12/
D3
D2
D1
D0
P02
P11
P10
P01
P00
P27/IN7
P26/IN6
P25/IN5
P24/IN4
P23/IN3
P22/IN2
P21/IN1
P20/IN0
VREF
10
11
12
13
14
15
16
17
18
P43
P42
P41
A14
P40
A13
VPP
OE
P33/CNTR1
P32/CNTR0
P31/INT1
P30/INT0
RESET
P51/XCOUT
P50/XCIN
VCC
A3
A2
A1
A12
A11
A0
CE
XIN
19
20
21
VSS
XOUT
VSS
VSS
VCC
: Same functions as M5L27256
Fig. 28 Pin connection in EPROM mode
35
ETC [ ETC ]
