Toshiba TC9349AFG Manual page 54

External Interrupt and Timer Counter Functions
There are two types of pin for external interrupt: INTR1 and INTR2. An interrupt request is issued on detection of the
edge of the signal applied to pins INTR1 and INTR2, whether rising, falling or both. The interrupt input pins also combine
the functions of I/O port; break during backup; and, in the case of the INTR2 pin, PLL
The timer counter is an 8-bit binary counter and has timer mode and pulse width measurement mode functions. In pulse
width measurement mode, the pulse width input from the external interrupt pin (INTR1) is measured. This can be used for
purposes such as detecting the leader pulse of a remote control.
1. External Interrupt Function
There are two types of pin for external interrupt, INTR1 and INTR2, and an interrupt request is issued on detection of the
edge of these inputs. The inputs incorporate a Schmitt circuit and a noise canceller, the frequency of the CPU clock
(low-speed oscillation clock: 75 kHz; high-speed oscillation clock: 300 ∼ 600 kHz) being used for the noise-filtering clock.
Any pulse of less than 1 ~ 3 clocks of the CPU clock is removed as noise; and an interrupt is generated when a pulse at or
over 1 ~ 3 clocks of the CPU clock (at the time of a 75 kHz oscillation: 13.3 ~ 40 µs) is input. Either the rising or the falling
edge, or both, can be selected for each pin.
The pin used for the external interrupt function also serves as an I/O port. Interrupt will be permitted if edge selection is
enabled through use of the external interrupt control port. The external interrupt input state can be read from the I/O port 4
input data port (φK33), which is used in combination.
The INTR1 pin is used in combination with the input pin of the pulse width measurement mode function of the timer
counter. The INTR1 control port is also used to control the logical setting of the pulse.
(Refer to the section on the timer counter.)
The external interrupt of the INTR2 pin is selected together with the timer port interrupt. When external interrupt of the
INTR2 pin is used, it is necessary to set the timer port. (Refer to the sections on the timer port and on changing the interrupt
factor.) The program will branch to address 0001H if an INTR1 pin interrupt is received, to address 0002H if an INTR2 pin
interrupt is received.
Y1 Y2 Y4
φ
POS1 NEG1 POS2
L22
INTR1 INTR2
Control Control
Note: The function becomes effective when
the external interrupt function.
Note: When interrupt is permitted, the I/O port 4 control port becomes invalid and is forced to change to an
input port.
Y8
NEG2
INTR2 external interruption / Control of timer port interruption
POS2 NEG2
100/200Hz timer interrupt
0 0
1 0
External interrupt of INTR2 pin
0 1
1 1
Control of INTR1 external interruption
POS1 NEG1
0
0 External interrupt prohibition
1
0
0
1 External interrupt of INTR1 pin
1 1
INH
54
INH
Interrupt Function
Interrupt Function
input function and break function are permitted on setting of
TC9349AFG
input pin.
Edge Select
I/O port function
Rising edge
Falling edge
Both edges
Edge Select
I/O port function
Rising edge
Falling edge
Both edges
2006-02-24