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Interrupt Function
INTR1 and INTR2 are the input pins for the external interrupts. These pins can also be used for remote
control signal input and tape running detection input. The pins can also be set as general-purpose input ports
by software.
1. Interrupt Function
The interrupt function consists of two external interrupt sources: interrupt 1 and interrupt 2. The
function supports prioritized multiple interrupts. The interrupt circuit is set using an internal port.
Interrupts are received based on the signals input to the corresponding pins (INTR1, INTR2).
Interrupt 1 is suitable for use as the remote control interrupt. If the interrupt source input is at high
level (with the interrupt signal set for positive logic input) for longer than the time set by the counter
circuit (0.3~12.5 ms), the signal is recognized as an interrupt. Interrupt 2 is suitable for detecting the end
of tape in a cassette deck. The interrupt function begins measuring on a rising edge (with the interrupt
signal set for positive logic input). If no other rising edge occurs within the time set by positive logic input).
If no other rising edge occurs within the time set by the counter circuit (0.1~6.2 s), the signal is
recognized as an interrupt.
If the counter setting data are "01H" for either interrupt 1 or interrupt 2, for a pulse of 120 µs or longer
the interrupt can be received.
The input pins are Schmitt inputs. Moreover, because an internal noise rejection circuit is provided,
noise pulses of less than 80~120 µs are not detected. The input logic is controlled by an internal port
setting to suit various input signals.
External
Interrupt
INTR1
•
Schmitt input
(interrupt 1)
•
Input logic level
INTR2
control
(interrupt 2)
Input Pin
Interrupt Signal Detection Width
Minimum detection width 120 µs
Timer interrupt time 0.3~12.5 ms
Minimum detection width 120 µs
Timer interrupt time 0.1~6.2 s
44
TC9314F
Enable
Priority
Condition
INTE1 = 1
1
Address 1
IEF1 = 1
INTE2 = 1
2
Address 2
IEF2 = 1
2003-07-03
Entry
Address
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