ATtiny28L

Manufacturer Part NumberATtiny28L
ManufacturerAtmel Corporation
ATtiny28L datasheets
 


Specifications of ATtiny28L

Flash (kbytes)2 KbytesPin Count28
Max. Operating Frequency4 MHzCpu8-bit AVR
Hardware Qtouch AcquisitionNoMax I/o Pins11
Ext Interrupts10Usb SpeedNo
Usb InterfaceNoGraphic LcdNo
Video DecoderNoCamera InterfaceNo
Analog Comparators1Resistive Touch ScreenNo
Temp. SensorNoCrypto EngineNo
Sram (kbytes)0.03Self Program MemoryNO
Dram MemoryNoNand InterfaceNo
PicopowerNoTemp. Range (deg C)-40 to 85
I/o Supply Class1.8 to 5.5Operating Voltage (vcc)1.8 to 5.5
FpuNoMpu / Mmuno / no
Timers132khz RtcNo
Calibrated Rc OscillatorYes  
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Register Description
Modulation Control Register –
MODCR
Table 18. MCONF2..0 Effect on Duty-cycle and Modulation Period
MCONF2..0
On-time
000
X
001
ONTIM+1
010
ONTIM+1
011
ONTIM+1
100
2 x (ONTIM+1)
101
3 x (ONTIM+1)
110
111
X
Note:
In the high-frequency mode, the output is gated with the clock signal. Thus, the on- and off-times will be dependent on the clock
input to the MCU. Also note that when changing from this mode directly to another modulation mode, the output will have a
small glitch. Thus, PA2 should be set to stop the modulated output before changing from this mode.
1062F–AVR–07/06
Bit
7
6
5
$02
ONTIM4
ONTIM3
ONTIM2
Read/Write
R/W
R/W
R/W
Initial Value
0
0
0
• Bits 7..3 – ONTIM4..0: Modulation On-time
This 5-bit value +1 determines the number of clock cycles the output pin PA2 is active
(low).
• Bits 2..0 – MCONF2..0: Modulation Configuration Bits 2, 1 and 0
These three bits determine the relationship between the on- and off-times of the modu-
lator, and thereby the duty-cycle. The various settings are shown in Table 18. The
minimum and maximum modulation period is also shown in the table. The minimum
modulation period is obtained by setting ONTIM to zero, while the maximum period is
obtained by setting ONTIM to 31. The configuration values for some common oscillator
and carrier frequencies are listed in Table 17. The relationship between oscillator fre-
quency and carrier frequency is:
fcarrier
If the MCONF register is set to 111, the carrier frequency will be equal to the oscillator
frequency.
Off-time
Duty-cycle
Min Period
X
100%
X
ONTIM+1
50%
2 CK
2 x (ONTIM+1)
33%
3 CK
3 x (ONTIM+1)
25%
4 CK
ONTIM+1
67%
3 CK
ONTIM+1
75%
4 CK
Reserved
X
Note 1
1 CK
ATtiny28L/V
4
3
2
1
ONTIM1
ONTIM0
MCONF2
MCONF1
R/W
R/W
R/W
R/W
0
0
0
0
fosc
=
-----------------------------------------------------
(
)
On-time
+
Off-time
Max Period
Comment
X
Unmodulated output
64 CK
96 CK
128 CK
96 CK
128 CK
1 CK
High-frequency output
0
MCONF0
MODCR
R/W
0
43