M37754M8C-XXXGP Datasheet, PDF (22/114 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16BIT CMOS MICROCOMPUTER

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MITSUBISHI MICROCOMPUTERS
M37754M8C-XXXGP, M37754M8C-XXXHP
M37754S4CGP, M37754S4CHP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
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The INT3 interrupt can function as the key input interrupt by setting
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bits 7 and 6 of the INT3 interrupt control register. The key input inter-
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rupt uses inputs KI3 to KI0 or inputs KI4 to KI0. Figure 10 shows the
interrupt control register bit configuration. Figure 15 shows the par-
ticular function select register 1 bit configuration, and Figure 16
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shows the INT3/key input interrupt input circuit block diagram.
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When the INT3 interrupt control register’s bit 7 is “0” and its bit 6 is
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“0”, a signal from the INT3 pin is connected to the INT3 interrupt con-
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trol circuit and INT3 external interrupt is normally performed.
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When the INT3 interrupt control register’s bit 7 is “1” and its bit 6 is
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“0”, signals from the KI3 to KI0 pins, which correspond to ports P57 to
P54, are inverted and then the logical sum of these signals is con-
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nected to the INT3 interrupt control circuit. In this case, the external
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interrupt which uses the KI3 to KI0 pins is performed.
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When the INT3 interrupt control register’s bit 7 is “1” and its bit 6 is
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“1”, signals from the KI4 pin, which corresponds to port P95, KI3 to
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KI0 pins, which correspond to ports P57 to P54, are inverted and then
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the logical sum of these signals is connected to the INT3 interrupt
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control circuit. In this case, the external interrupt which uses the KI4
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to KI0 pins is performed.
When using the above key input interrupt, select the edge sense
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which uses the falling edge from “H” to “L” with the INT3 interrupt
control register so that an interrupt request can occur by inputting “L”
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to each of the KI3 to KI0 pins or the KI4 to KI0 pins. The interrupt vec-
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tor is common to the INT3 interrupt’s one. Additionally, pull-up resis-
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tor (transistors) can be added to the KI4 to KI0 pins by setting the
contents of the particular function select register 1’s bits 7 and 6 and
setting “0” to each bit of the corresponding port’s direction register.
P95/INT3/KI4
Pull-up select bit 1
Port P95 direction register
Key input interrupt select bit 0
(Bit 6 of INT3 interrupt control register)
Pull-up
transistor
P57/TA3IN/KI3
Pull-up select bit 0
Port P57 direction
register
Pull-up
transistor
P56/TA3OUT/KI2
Pull-up
transistor
P55/TA2IN/KI1
Pull-up
transistor
P54/TA2OUT/KI0
Port P56 direction
register
Port P55 direction
register
Port P54 direction
register
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Fig. 16 INT3/key input interrupt input circuit block diagram
INT3 interrupt control register (Address 6F16)
Key input interrupt select bit 1
Bit 7 of INT3 interrupt
control register
When the key input interrupt
is selected, select the edge
sense which uses falling edge
from “H” to “L”.
0
Interrupt control circuit INT3 interrupt request
1
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