MITSUBISHI MICROCOMPUTERS
M37754M8C-XXXGP, M37754M8C-XXXHP
M37754S4CGP, M37754S4CHP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
The INT3 interrupt can function as the key input interrupt by setting
to KI0 pins is performed.
bits 7 and 6 of the INT3 interrupt control register. The key input inter-
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
shows the INT3/key input interrupt input circuit block diagram.
When the INT3 interrupt control register’s bit 7 is “0” and its bit 6 is
“0”, a signal from the INT3 pin is connected to the INT3 interrupt con-
trol circuit and INT3 external interrupt is normally performed.
When the INT3 interrupt control register’s bit 7 is “1” and its bit 6 is
“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-
nected to the INT3 interrupt control circuit. In this case, the external
interrupt which uses the KI3 to KI0 pins is performed.
When using the above key input interrupt, select the edge sense
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”
to each of the KI3 to KI0 pins or the KI4 to KI0 pins. The interrupt vec-
tor is common to the INT3 interrupt’s one. Additionally, pull-up resis-
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.
When the INT3 interrupt control register’s bit 7 is “1” and its bit 6 is
“1”, signals from the KI4 pin, which corresponds to port P95, KI3 to
KI0 pins, which correspond to ports P57 to P54, are inverted and then
the logical sum of these signals is connected to the INT3 interrupt
control circuit. In this case, the external interrupt which uses the KI4
INT3 interrupt control register
(Address 6F16)
Pull-up select bit 1
Port P95 direction register
When the key input interrupt
is selected, select the edge
sense which uses falling edge
from “H” to “L”.
P95/INT3/KI4
Key input interrupt select bit 1
Bit 7 of INT interrupt
control register
3
Key input interrupt select bit 0
(Bit 6 of INT3 interrupt control register)
0
Interrupt control circuit
INT3 interrupt request
Pull-up select bit 0
Port P57 direction
register
Pull-up
transistor
1
P57/TA3IN/KI3
Pull-up
transistor
Port P56 direction
register
P56/TA3OUT/KI2
Pull-up
transistor
Port P55 direction
register
P55/TA2IN/KI1
Pull-up
Port P54 direction
register
transistor
P54/TA2OUT/KI0
Fig. 16 INT3/key input interrupt input circuit block diagram
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RENESAS [ RENESAS TECHNOLOGY CORP ]
