Datasheet

51
8183F–AVR–06/12
ATtiny24A/44A/84A
• Bit 4 – PCIE0: Pin Change Interrupt Enable 0
When the PCIE0 bit is set (one) and the I-bit in the Status Register (SREG) is set (one), pin
change interrupt 0 is enabled. Any change on any enabled PCINT[7:0] pin will cause an inter-
rupt. The corresponding interrupt of Pin Change Interrupt Request is executed from the PCI0
Interrupt Vector. PCINT[7:0] pins are enabled individually by the PCMSK0 Register.
9.3.3 GIFR – General Interrupt Flag Register
• Bits 7, 3:0 – Res: Reserved Bits
These bits are reserved in the ATtiny24A/44A and will always read as zero.
• Bit 6 – INTF0: External Interrupt Flag 0
When an edge or logic change 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 cor-
responding Interrupt Vector. The flag is cleared when the interrupt routine is executed.
Alternatively, the flag can be cleared by writing a logical one to it. This flag is always cleared
when INT0 is configured as a level interrupt.
• Bit 5 – PCIF1: Pin Change Interrupt Flag 1
When a logic change on any PCINT[11:8] pin triggers an interrupt request, PCIF1 becomes set
(one). If the I-bit in SREG and the PCIE1 bit in GIMSK are set (one), the MCU will jump to the
corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alter-
natively, the flag can be cleared by writing a logical one to it.
• Bit 4 – PCIF0: Pin Change Interrupt Flag 0
When a logic change on any PCINT[7:0] pin triggers an interrupt request, PCIF becomes set
(one). If the I-bit in SREG and the PCIE0 bit in GIMSK are set (one), the MCU will jump to the
corresponding Interrupt Vector. The flag is cleared when the interrupt routine is executed. Alter-
natively, the flag can be cleared by writing a logical one to it.
9.3.4 PCMSK1 – Pin Change Mask Register 1
• Bits 7:4 – Res: Reserved Bits
These bits are reserved in the ATtiny24A/44A and will always read as zero.
• Bits 3:0 – PCINT[11:8]: Pin Change Enable Mask 11:8
Each PCINT[11:8] bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT[11:8] is set and the PCIE1 bit in GIMSK is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT[11:8] is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
Bit 76543210
0x3A (0x5A) –INTF0PCIF1PCIF0––––GIFR
Read/Write R R/W R/W R/W R R R R
Initial Value 0 0 0 0 0 0 0 0
Bit 7 6 5 4 3 2 1 0
0x20 (0x40) – – – – PCINT11 PCINT10 PCINT9 PCINT8 PCMSK1
Read/Write R R R R R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0