ATMEGA8HVD-4MX Atmel, ATMEGA8HVD-4MX Datasheet - Page 77
ATMEGA8HVD-4MX
Manufacturer Part Number
ATMEGA8HVD-4MX
Description
MCU AVR 8K FLASH 2.1-8V 4MHZ QFN
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheet
1.ATMEGA8HVD-4MX.pdf
(168 pages)
Specifications of ATMEGA8HVD-4MX
Core Processor
AVR
Core Size
8-Bit
Speed
4MHz
Peripherals
POR, WDT
Number Of I /o
5
Program Memory Size
8KB (4K x 16)
Program Memory Type
FLASH
Eeprom Size
256 x 8
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
2 V ~ 2.4 V
Data Converters
A/D 1x10b
Oscillator Type
Internal
Operating Temperature
-20°C ~ 85°C
Package / Case
18-MLF® Exposed Pad (Staggered Leads), DFN
For Use With
ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Connectivity
-
- Current page: 77 of 168
- Download datasheet (3Mb)
16.5.1
16.5.2
16.5.3
8052B–AVR–09/08
Normal 8-bit Mode
Clear Timer on Compare Match (CTC) 8-bit Mode
16-bit Mode
In the normal mode, the counter (TCNTnL) is incrementing until it overruns when it passes its
maximum 8-bit value (MAX = 0xFF) and then restarts from the bottom (0x00), see
on page 76
as the TCNTnL becomes zero. The TOVn Flag in this case behaves like a ninth bit, except
that it is only set, not cleared. However, combined with the timer overflow interrupt that auto-
matically clears the TOVn Flag, the timer resolution can be increased by software. There are
no special cases to consider in the Normal 8-bit mode, a new counter value can be written
anytime. The Output Compare Unit can be used to generate interrupts at some given time.
In Clear Timer on Compare or CTC mode, the OCRnA Register is used to manipulate the
counter resolution, see
cleared to zero when the counter value (TCNTn) matches the OCRnA. The OCRnA defines
the top value for the counter, hence also its resolution. This mode allows greater control of the
Compare Match output frequency. It also simplifies the operation of counting external events.
The timing diagram for the CTC mode is shown in
(TCNTn) increases until a Compare Match occurs between TCNTn and OCRnA, and then
counter (TCNTn) is cleared.
Figure 16-3. CTC Mode, Timing Diagram
An interrupt can be generated each time the counter value reaches the TOP value by using
the OCFnA Flag. If the interrupt is enabled, the interrupt handler routine can be used for
updating the TOP value. However, changing TOP to a value close to BOTTOM when the
counter is running with none or a low prescaler value must be done with care since the CTC
mode does not have the double buffering feature. If the new value written to OCRnA is lower
than the current value of TCNTn, the counter will miss the Compare Match. The counter will
then have to count to its maximum value (0xFF) and wrap around starting at 0x00 before the
Compare Match can occur. As for the Normal mode of operation, the TOVn Flag is set in the
same timer clock cycle that the counter counts from MAX to 0x00.
In 16-bit mode, the counter (TCNTnH/L) is a incrementing until it overruns when it passes its
maximum 16-bit value (MAX = 0xFFFF) and then restarts from the bottom (0x0000), see
16-2 on page 76
cycle as the TCNTnH/L becomes zero. The TOVn Flag in this case behaves like a 17th bit,
except that it is only set, not cleared. However, combined with the timer overflow interrupt that
automatically clears the TOVn Flag, the timer resolution can be increased by software. There
TCNTn
Period
for bit settings. The Overflow Flag (TOVn) will be set in the same timer clock cycle
for bit settings. The Overflow Flag (TOVn) will be set in the same timer clock
1
Table 16-2 on page 76
2
3
for bit settings. In CTC mode the counter is
Figure 16-3 on page
4
ATmega4HVD/8HVD
77. The counter value
OCnx Interrupt Flag Set
Table 16-2
Table
77
Related parts for ATMEGA8HVD-4MX
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
IC AVR MCU 2.4GHZ XCEIVER 64QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA644/AT86RF230 40-DIP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA644P/AT86RF230 QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA644P/AT86RF230 TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA1281/AT86RF230 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA1280/AT86RF230 100TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA1280/AT86RF100-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
BUNDLE ATMEGA2560V/AT86RF230-ZU
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU ATMEGA2561/AT86RF230 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet: