ATMEGA48-20AJ Atmel, ATMEGA48-20AJ Datasheet - Page 69

• Manufacturer Part Number: ATMEGA48-20AJ
• Description: IC AVR MCU 4K 5V 20MHZ 32-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48-20AJ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ATMEGA48-24AJ; ATMEGA48-24AJ

12.2.6
12.2.7
12.2.8
2545S–AVR–07/10
PCMSK2 – Pin Change Mask Register 2
PCMSK1 – Pin Change Mask Register 1
PCMSK0 – Pin Change Mask Register 0
• Bit 0 - PCIF0: Pin Change Interrupt Flag 0
When a logic change on any PCINT7..0 pin triggers an interrupt request, PCIF0 becomes set
(one). If the I-bit in SREG and the PCIE0 bit in PCICR 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 7..0 – PCINT23..16: Pin Change Enable Mask 23..16
Each PCINT23..16-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT23..16 is set and the PCIE2 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT23..16 is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
• Bit 7 – Res: Reserved Bit
This bit is an unused bit in the ATmega48/88/168, and will always read as zero.
• Bit 6..0 – PCINT14..8: Pin Change Enable Mask 14..8
Each PCINT14..8-bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT14..8 is set and the PCIE1 bit in PCICR is set, pin change interrupt is enabled on
the corresponding I/O pin. If PCINT14..8 is cleared, pin change interrupt on the corresponding
I/O pin is disabled.
• Bit 7..0 – PCINT7..0: Pin Change Enable Mask 7..0
Each PCINT7..0 bit selects whether pin change interrupt is enabled on the corresponding I/O
pin. If PCINT7..0 is set and the PCIE0 bit in PCICR is set, pin change interrupt is enabled on the
corresponding I/O pin. If PCINT7..0 is cleared, pin change interrupt on the corresponding I/O pin
is disabled.
Bit
(0x6D)
Read/Write
Initial Value
Bit
(0x6C)
Read/Write
Initial Value
Bit
(0x6B)
Read/Write
Initial Value
PCINT23
R/W
7
PCINT7
R/W
0
7
0
R
7
–
0
PCINT22
6
PCINT6
R/W
0
R/W
PCINT14
6
0
R/W
6
0
PCINT21
5
PCINT5
R/W
0
R/W
PCINT13
5
0
R/W
5
0
PCINT20
4
PCINT4
R/W
0
R/W
PCINT12
4
0
R/W
4
0
PCINT19
3
PCINT3
R/W
0
PCINT11
R/W
3
0
R/W
3
0
PCINT18
2
PCINT2
R/W
0
PCINT10
R/W
ATmega48/88/168
2
0
R/W
2
0
PCINT17
1
PCINT1
R/W
0
PCINT9
R/W
R/W
1
0
1
0
0
PCINT0
R/W
0
PCINT16
PCINT8
R/W
R/W
0
0
0
0
PCMSK0
PCMSK2
PCMSK1
69