ATtiny28L Atmel Corporation, ATtiny28L Datasheet - Page 7

no-image

ATtiny28L

Manufacturer Part Number
ATtiny28L
Description
Manufacturer
Atmel Corporation
Datasheets

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
System Clock and
Clock Options
Internal RC Oscillator
Calibrated Internal RC
Oscillator
Crystal Oscillator
External Clock
1062F–AVR–07/06
The device has the following clock source options, selectable by Flash Fuse bits as
shown in Table 1.
Table 1. Device Clocking Option Select
Clock Option
External Crystal/Ceramic Resonator
External Low-frequency Crystal
External RC Oscillator
Internal RC Oscillator
External Clock
Note:
“1” means unprogrammed, “0” means programmed.
The various choices for each clocking option give different start-up times as shown in
Table 5 on page 16.
The internal RC oscillator option is an on-chip calibrated oscillator running at a nominal
frequency of 1.2 MHz. If selected, the device can operate with no external components.
The device is shipped with this option selected.
The calibrated internal oscillator provides a fixed 1.2 MHz (nominal) clock at 3V and
25°C. This clock may be used as the system clock. This oscillator can be calibrated by
writing the calibration byte to the OSCCAL register. When this oscillator is used as the
chip clock, the Watchdog oscillator will still be used for the Watchdog Timer and for the
reset time-out. For details on how to use the pre-programmed calibration value, see the
section “Calibration Byte” on page 46.
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier, which
can be configured for use as an on-chip oscillator, as shown in Figure 5. Either a quartz
crystal or a ceramic resonator may be used. When the INTCAP fuse is programmed,
internal load capacitors with typical values 50 pF are connected between XTAL1/XTAL2
and ground.
Figure 5. Oscillator Connections
Note:
1. When using the MCU oscillator as a clock for an external device, an HC buffer should
be connected as indicated in the figure.
To drive the device from an external clock source, XTAL2 should be left unconnected
while XTAL1 is driven as shown in Figure 6.
ATtiny28L/V
MAX 1 HC BUFFER
HC
C2
XTAL2
C1
XTAL1
GND
CKSEL3..0
1111 - 1010
1001 - 1000
0111 - 0101
0100 - 0010
0001 - 0000
7

Related parts for ATtiny28L