ATtiny28L Atmel Corporation, ATtiny28L Datasheet - Page 32

• Manufacturer Part Number: ATtiny28L
• Manufacturer: Atmel Corporation

Specifications of ATtiny28L

• Flash (kbytes): 2 Kbytes
• Pin Count: 28
• Max. Operating Frequency: 4 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 11
• Ext Interrupts: 10
• Usb Speed: No
• Usb Interface: No
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.03
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 1
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

Register Description
Port A Data Register – PORTA
Port A Control Register –
PACR
Port A Input Pins Address –
PINA
Port B Input Pins Address –
PINB
32
ATtiny28L/V
• Bits 7..4 – Res: Reserved Bits
These bits are reserved bits in the ATtiny28 and always read as zero.
• Bit 3 – DDA3: Data Direction PA3
When DDA3 is set (one), the corresponding pin is an output pin. Otherwise, it is an input
pin.
• Bit 2 – PA2HC: PORTA2 High Current Enable
When the PA2HC bit is set (one), an additional driver at the output pin PA2 is enabled.
This makes it possible to sink 25 mA at V
cleared (zero), PA2 can sink 15 mA at V
• Bits 1, 0 – DDA1, DDA0: Data Direction PA1 and PA0
When DDAn is set (one), the corresponding pin is an output pin. Otherwise, it is an input
pin.
The Port A Input Pins address (PINA) is not a register; this address enables access to
the physical value on each Port A pin. When reading PORTA, the Port A Data Latch is
read and when reading PINA, the logical values present on the pins are read.
The Port B Input Pins address (PINB) is not a register; this address enables access to
the physical value on each Port B pin. When reading PINB, the logical values present on
the pins are read.
Bit
$1B
Read/Write
Initial Value
Bit
$1A
Read/Write
Initial Value
Bit
$19
Read/Write
Initial Value
Initial Value
Read/Write
$16
Bit
PINB7
N/A
R
R
R
R
7
–
0
7
–
0
7
–
0
7
PINB6
N/A
R
R
R
R
6
–
0
6
–
0
6
–
0
6
PINB5
N/A
5
R
0
5
–
R
0
5
–
R
0
5
R
–
PINB4
N/A
R
R
CC
R
R
4
–
0
4
–
0
4
–
0
4
CC
= 1.8V (V
= 1.8V (V
PORTA3
PINA3
PINB3
DDA3
R/W
R/W
N/A
N/A
R
R
3
0
3
0
3
3
OL
OL
PORTA2
PA2HC
= 0.8V).
PINB2
= 0.8V). When the PA2HC bit is
R/W
R/W
N/A
R
R
2
1
2
0
2
–
0
2
PORTA1
PINA1
PINB1
DDA1
R/W
R/W
N/A
N/A
R
R
1
0
1
0
1
1
PORTA0
PINA0
PINB0
DDA0
R/W
R/W
N/A
N/A
R
R
0
0
0
0
0
0
1062F–AVR–07/06
PORTA
PACR
PINA
PINB