TINY12 ATMEL [ATMEL Corporation], TINY12 Datasheet - Page 5

• Manufacturer Part Number: TINY12
• Description: 8-bit AVR Microcontroller with 1K Byte Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Pin Descriptions
VCC
GND
Port B (PB5..PB0)
XTAL1
XTAL2
RESET
Clock Options
1006D–AVR–07/03
The ATtiny12 AVR is supported with a full suite of program and system development
tools including: macro assemblers, program debugger/simulators, in-circuit emulators,
and evaluation kits.
Supply voltage pin.
Ground pin.
Port B is a 6-bit I/O port. PB4..0 are I/O pins that can provide internal pull-ups (selected
for each bit). On ATtiny11, PB5 is input only. On ATtiny12, PB5 is input or open-drain
output. The port pins are tri-stated when a reset condition becomes active, even if the
clock is not running. The use of pins PB5..3 as input or I/O pins is limited, depending on
reset and clock settings, as shown below.
Table 2. PB5..PB3 Functionality vs. Device Clocking Options
Notes:
Input to the inverting oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting oscillator amplifier.
Reset input. An external reset is generated by a low level on the RESET pin. Reset
pulses longer than 50 ns will generate a reset, even if the clock is not running. Shorter
pulses are not guaranteed to generate a reset.
The device has the following clock source options, selectable by Flash fuse bits as
shown:
Table 3. Device Clocking Options Select
Device Clocking Option
External Reset Enabled
External Reset Disabled
External Crystal
External Low-frequency Crystal
External Ceramic Resonator
External RC Oscillator
External Clock
Internal RC Oscillator
Device Clocking Option
External Crystal/Ceramic Resonator
External Low-frequency Crystal
External RC Oscillator
1. “Used” means the pin is used for reset or clock purposes.
2. “-” means the pin function is unaffected by the option.
3. Input means the pin is a port input pin.
4. On ATtiny11, PB5 is input only. On ATtiny12, PB5 is input or open-drain output.
5. I/O means the pin is a port input/output pin.
ATtiny11 CKSEL2..0
111
110
101
Input
Used
PB5
(3)
-
-
-
-
-
-
/I/O
(1)
(4)
ATtiny11/12
ATtiny12 CKSEL3..0
Used
Used
Used
I/O
PB4
I/O
I/O
-
1111 - 1010
1001 - 1000
0111 - 0101
(2)
-
(5)
Used
Used
Used
Used
Used
PB3
I/O
-
-
5