ATmega32C1 Automotive Atmel Corporation, ATmega32C1 Automotive Datasheet - Page 88

• Manufacturer Part Number: ATmega32C1 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega32C1 Automotive

• Flash (kbytes): 32 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

11.3.1
88
Atmel ATmega16/32/64/M1/C1
General Timer/Counter Control Register – GTCCR
Enabling and disabling of the clock input must be done when Tn/T0 has been stable for at
least one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is
generated.
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
uses sampling, the maximum frequency of an external clock it can detect is half the sampling
frequency (Nyquist sampling theorem). However, due to variation of the system clock fre-
quency 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 11-2. Prescaler for Timer/Counter0 and Timer/Counter1
Note:
• Bit 7 – TSM: Timer/Counter Synchronization Mode
Writing the TSM bit to one activates the Timer/Counter Synchronization mode. In this mode,
the value that is written to the PSRSYNC bit is kept, hence keeping the corresponding pres-
caler reset signals asserted. This ensures that the corresponding Timer/Counters are halted
and can be configured to the same value without the risk of one of them advancing during con-
figuration. When the TSM bit is written to zero, the PSRSYNC bit is cleared by hardware, and
the Timer/Counters start counting simultaneously.
Bit
Read/Write
Initial Value
PSRSYNC
clk_I/O
clk
T0
T1
1. The synchronization logic on the input pins (
I/O
/2.5.
Synchronization
Synchronization
TSM
R/W
7
0
ICPSEL1
R/W
6
0
ExtClk
< f
clk_I/O
R
5
–
0
/2) given a 50/50% duty cycle. Since the edge detector
clk
Clear
T1
R
4
–
0
R
3
–
0
Tn)
is shown in
R
2
–
0
(1)
Figure
R
1
–
0
11-1.
clk
PSRSYNC
T0
R/W
0
0
7647G–AVR–09/11
GTCCR