ATTINY861A-SU Atmel, ATTINY861A-SU Datasheet - Page 94

• Manufacturer Part Number: ATTINY861A-SU
• Description: IC, MCU, 8BIT, 8K FLASH, 20SOIC
• Manufacturer: Atmel

Specifications of ATTINY861A-SU

• Controller Family/series: ATtiny
• No. Of I/o's: 16
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 20MHz
• No.: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 8KB
• Oscillator Type: External, Internal
• Rohs Compliant: Yes

12.6
94
Dead Time Generator
ATtiny261A/461A/861A
The Dead Time Generator is provided for the Timer/Counter1 PWM output pairs to allow driving
external power control switches safely. The Dead Time Generator is a separate block that can
be used to insert dead times (non-overlapping times) for the Timer/Counter1 complementary
output pairs OC1x and OC1x when the PWM mode is enabled and the COM1x1:0 bits are set to
“01”. See
Figure 12-7. Block Diagram of Waveform Generator and Dead Time Generator.
The tasks are shared as follows: the Waveform Generator generates the output (OCW1x) and
the Dead Time Generator generates the non-overlapping PWM output pair from the output.
Three Dead Time Generators are provided, one for each PWM output. The non-overlap time is
adjustable and the PWM output and it’s complementary output are adjusted separately, and
independently for both PWM outputs.
The Dead Time Generation is based on 4-bit down counters that count the dead time, as shown
in
Figure 12-8. Dead Time Generator
There is a dedicated prescaler in front of the Dead Time Generator that can divide the
Timer/Counter1 clock (PCK or CK) by 1, 2, 4 or 8. This provides for large range of dead times
that can be generated. The prescaler is controlled by two control bits DTPS11:10. The block has
also a rising and falling edge detector that is used to start the dead time counting period.
Depending on the edge, one of the transitions on the rising edges, OC1x or OC1x is delayed
until the counter has counted to zero. The comparator is used to compare the counter with zero
and stop the dead time insertion when zero has been reached. The counter is loaded with a 4-bit
DT1H or DT1L value from DT1 I/O register, depending on the edge of the Waveform Output
(OCW1x) when the dead time insertion is started. The Output Compare Output are delayed by
one timer clock cycle at minimum from the Waveform Output when the Dead Time is adjusted to
CK OR PCK
bottom
OCWnx
FOCn
Figure
CLOCK
top
TCCRnB REGISTER
12-8.
Figure 12-7
PRE-SCALER
DEAD TIME
PWMnx
Waveform Generator
below.
WGM10
CLOCK CONTROL
COMnx
CK OR PCK
OCWnx
CLOCK
DTn I/O REGISTER
4-BIT COUNTER
COMPARATOR
DTPSn
Dead Time Generator
DATA BUS (8-bit)
DTnH
DTnL
OCnx
OCnx
PWM1X
PWM1X
8197B–AVR–01/10
OCnx
OCnx
OCnx
OCnx
pin
pin