ATmega8535 Atmel Corporation, ATmega8535 Datasheet - Page 88

• Manufacturer Part Number: ATmega8535
• Manufacturer: Atmel Corporation

Specifications of ATmega8535

• Flash (kbytes): 8 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Special Function IO Register –
SFIOR
88
ATmega8535(L)
Each half period of the external clock applied must be longer than one system clock
cycle to ensure correct sampling. The external clock must be guaranteed to have less
than half the system clock frequency (f
the edge detector uses sampling, the maximum frequency of an external clock it can
detect is half the sampling frequency (Nyquist sampling theorem). However, due to vari-
ation of the system clock frequency and duty cycle caused by Oscillator source (crystal,
resonator, and capacitors) tolerances, it is recommended that maximum frequency of an
external clock source is less than f
An external clock source can not be prescaled.
Figure 39. Prescaler for Timer/Counter0 and Timer/Counter1
Note:
• Bit 0 – PSR10: Prescaler Reset Timer/Counter1 and Timer/Counter0
When this bit is written to one, the Timer/Counter1 and Timer/Counter0 prescaler will be
reset. The bit will be cleared by hardware after the operation is performed. Writing a
zero to this bit will have no effect. Note that Timer/Counter1 and Timer/Counter0 share
the same prescaler and a reset of this prescaler will affect both timers. This bit will
always be read as zero.
Bit
Read/Write
Initial Value
PSR10
clk
T0
T1
I/O
1. The synchronization logic on the input pins (
Synchronization
Synchronization
ADTS2
R/W
7
0
ADTS1
R/W
6
0
ADTS0
R/W
5
0
clk_I/O
clk
Clear
T1
ExtClk
/2.5.
R
4
–
0
< f
clk_I/O
ACME
R/W
3
0
T1/T0)
/2) given a 50/50% duty cycle. Since
PUD
R/W
is shown in Figure 38.
2
0
(1)
PSR2
R/W
1
0
clk
PSR10
T0
R/W
2502K–AVR–10/06
0
0
SFIOR