ATtiny15L
19
The General Interrupt Mask Register – GIMSK
•
Bit 7 - Res: Reserved Bit
This bit is a reserved bit in the ATtiny15L and always reads as zero.
•
Bit 6 - INT0: External Interrupt Request 0 Enable
When the INT0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), the external pin interrupt is activated.
The Interrupt Sense Control0 bits 1/0 (ISC01 and ISC00) in the MCU general Control Register (MCUCR) defines whether
the external interrupt is activated on rising or falling edge, on pin change, or low-level of the INT0 pin. Activity on the pin will
cause an interrupt request even if INT0 is configured as an output. The corresponding interrupt of External Interrupt
Request 0 is executed from program memory address $001. See also “External Interrupts.”
•
Bit 5 - PCIE: Pin Change Interrupt Enable
When the PCIE bit is set (one) and the I-bit in the status register (SREG) is set (one), the interrupt on pin change is
enabled. Any change on any input or I/O pin will cause an interrupt. The corresponding interrupt of Pin Change Interrupt
Request is executed from program memory address $002. See also “Pin Change Interrupt.”
•
Bits 4..0 - Res: Reserved bits
These bits are reserved bits in the ATtiny15L and always read as zero.
The General Interrupt Flag Register – GIFR
•
Bit 7 - Res: Reserved Bit
This bit is a reserved bit in the ATtiny15L and always reads as zero.
•
Bit 6 - INTF0: External Interrupt Flag0
When an event on the INT0 pin triggers an interrupt request, INTF0 becomes set (one). If the I-bit in SREG and the INT0 bit
in GIMSK are set (one), the MCU will jump to the interrupt vector at address $001. The flag is cleared when the interrupt
routine is executed. Alternatively, the flag can be cleared by writing a logical one to it. The flag is always cleared when INT0
is configured as level interrupt.
•
Bit 5 - PCIF: Pin Change Interrupt Flag
When an event on any input or I/O pin triggers an interrupt request, PCIF becomes set (one). If the I-bit in SREG and the
PCIE bit in GIMSK are set (one), the MCU will jump to the interrupt vector at address $002. The flag is cleared when the
interrupt routine is executed. Alternatively, the flag can be cleared by writing a logical one to it.
•
Bits 4..0 - Res: Reserved bits
These bits are reserved bits in the ATtiny15L and always read as zero.
Bit
7
6
5
4
3
2
1
0
$3B
-
INT0
PCIE
-
-
-
-
-
GIMSK
Read/Write
R
R/W
R/W
R
R
R
R
R
Initial value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
$3A
-
INTF0
PCIF
-
-
-
-
-
GIFR
Read/Write
R
R/W
R/W
R
R
R
R
R
Initial value
0
0
0
0
0
0
0
0
