ATmega16HVB Atmel Corporation, ATmega16HVB Datasheet - Page 28

• Manufacturer Part Number: ATmega16HVB
• Manufacturer: Atmel Corporation

Specifications of ATmega16HVB

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 8 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 17
• Ext Interrupts: 15
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1.9
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 1
• 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: 4.0 to 25
• Operating Voltage (vcc): 4.0 to 25
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

9.3
9.4
9.5
28
Clock startup sequence
Clock output
System clock prescaler
ATmega16HVB/32HVB
3. To determine a fixed value for the actual clock period independent of the die temperature,
When the CPU wakes up from Power-save, the CPU clock source is used to time the start-up,
ensuring a stable clock before instruction execution starts. When the CPU starts from reset,
there is an additional delay allowing the voltage regulator to reach a stable level before com-
mencing normal operation. The Ultra Low Power RC Oscillator is used for timing this real-time
part of the start-up time. Start-up times are determined by the SUT Fuses as shown in
on page
shown in
Table 9-3.
Note:
The CPU clock divided by two can be output to the PB1 pin. The CPU can enable the clock out-
put function by setting the CKOE bit in the MCU Control Register. The clock will not run in any
sleep modes.
The Atmel ATmega16HVB/32HVB has a System Clock Prescaler, used to prescale the Cali-
brated Fast RC Oscillator. The system clock can be divided by setting the
Prescale Register” on page
clock frequency as the requirement for power consumption and processing power changes. This
system clock will affect the clock frequency of the CPU and all synchronous peripherals. clk
clk
When switching between prescaler settings, the System Clock Prescaler ensures that no
glitches occurs in the clock system. It also ensures that no intermediate frequency is higher than
CPU
where T is the die temperature in Kelvin and THOT is the calibration temperature stored in
the Signature row. The die temperature can be found using the Voltage ADC, refer to section
”Voltage ADC – 7-channel general purpose 12-bit Sigma-Delta ADC” on page 116
details.
for example to determine the best setting of the Battery Protection timing, use the calibra-
tion byte ULP_RC_FRQ stored in the signature address space, refer to section
the signature row from software” on page 195
and clk
1. The actual value depends on the actual clock period of the Ultra Low Power RC Oscillator,
26. The number of Ultra Low Power RC Oscillator cycles used for each time-out is
Table
refer to
FLASH
Number of Ultra Low Power RC oscillator cycles.
Typical time-out
9-3.
”Ultra Low Power RC oscillator” on page 27
are divided by a factor as shown in
128ms
256ms
512ms
16ms
32ms
64ms
4ms
8ms
32, and this enables the user to decrease or increase the system
(1)
for details.
Table 9-4 on page
for details.
Number of cycles
16K
32K
64K
512
1K
2K
4K
8K
33.
”CLKPR – Clock
8042D–AVR–10/11
”Reading
Table 9-2
for
I/O
,