M34512M2 Datasheet, PDF (44/80 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
4512 Group
SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER
Clock signal f(XIN) is obtained by externally connecting a ceramic
resonator.
Connect this external circuit to pins XIN and XOUT at the shortest
distance. A feedback resistor is built in between pins XIN and XOUT.
When an external clock signal is input, connect the clock source to
XIN and leave XOUT open. When using an external clock, the maxi-
mum value of external clock oscillating frequency is shown in Table
22.
Table 22 Maximum value of external clock oscillation frequency
Supply voltage
Oscillation frequency (duty ratio)
VDD = 4.0 V to 5.5 V
3.0 MHz (40 % to 60 %)
XIN
CIN
4512
Note: Externally connect a
XOUT
damping resistor Rd de-
pending on the oscillation
frequency.
(A feedback resistor is
Rd
built-in.)
Use the resonator manu-
facturer’s recommended
COUT
value because constants
such as capacitance de-
pend on the resonator.
Fig. 38 Ceramic resonator external circuit
ROM ORDERING METHOD
Please submit the information described below when ordering
Mask ROM.
(1) Mask ROM Order Confirmation Form ..................................... 1
(2) Data to be written into mask ROM ............................... EPROM
(three sets containing the identical data)
(3) Mark Specification Form .......................................................... 1
4512
XIN
XOUT VDD
VSS
External oscillation circuit
Fig. 39 External clock input circuit
44