Datasheet

88
8197C–AVR–05/11
ATtiny261A/461A/861A
12. Timer/Counter1
12.1 Features
• 8/10-Bit Accuracy
• Three Independent Output Compare Units
• Clear Timer on Compare Match (Auto Reload)
• Glitch Free, Phase and Frequency Correct Pulse Width Modulator (PWM)
• Variable PWM Period
• High Speed Asynchronous and Synchronous Clocking with Dedicated Prescaler
• Independent Dead Time Generators for Each PWM Channel
• Fault Protection Unit Can Disable PWM Output Pins
• Five Independent Interrupt Sources (TOV1, OCF1A, OCD1B, OCF1D, FPF1)
12.2 Overview
Timer/Counter1 is a general purpose high speed Timer/Counter module, with three independent
Output Compare Units, and with PWM support.
The Timer/Counter1 features a high resolution and a high accuracy usage with the lower pres-
caling opportunities. It can also support three accurate and high speed Pulse Width Modulators
using clock speeds up to 64 MHz. In PWM mode Timer/Counter1 and the output compare regis-
ters serve as triple stand-alone PWMs with non-overlapping non-inverted and inverted outputs.
Similarly, the high prescaling opportunities make this unit useful for lower speed functions or
exact timing functions with infrequent actions. A simplified block diagram of the Timer/Counter1
is shown in Figure 12-1.
Figure 12-1. Timer/Counter1 Block Diagram
8-BIT DATABUS
T/C INT. FLAG
REGISTER (TIFR)
10-BIT COMPARATOR
8-BIT OUTPUT COMPARE
REGISTER A (OCR1A)
T/C INT. MASK
REGISTER (TIMSK)
TIMER/COUNTER1
(TCNT1)
DIRECTION
TIMER/COUNTER1 CONTROL LOGIC
OCF1B
TOV1
TOIE1
OCIE1B
OCIE1A
OCF1A
TOV1 OCF1B OC1AOCF1A
T/C CONTROL
REGISTER A (TCCR1A)
COM1B1
PWM1A
PWM1B
COM1B0
FOC1A
FOC1B
10-BIT COMPARATOR
8-BIT OUTPUT COMPARE
REGISTER B (OCR1B)
COM1A1
COM1A0
T/C CONTROL
REGISTER B (TCCR1B)
CS12
PSR1
CS11
CS10
CS13
OC1A
OC1B
OC1B
DEAD TIME GENERATOR
DEAD TIME GENERATOR
10-BIT COMPARATOR
8-BIT OUTPUT COMPARE
REGISTER C (OCR1C)
10-BIT COMPARATOR
8-BIT OUTPUT COMPARE
REGISTER D (OCR1D)
COM1A1
PWM1D
COM1A0
FOC1D
T/C CONTROL
REGISTER C (TCCR1C)
OCF1D
OCF1D
OCIE1D
OC1D
OC1D
DEAD TIME GENERATOR
PSR1
PSR1
OCW1A
OCW1B
OCW1D
2-BIT HIGH BYTE
REGISTER (TC1H)
W
GM11
FPEN1
T/C CONTROL
REGISTER D (TCCR1E)
COM1B1
COM1B0
COM1D1
COM1D0
FPNC1
FPES1
FPAC1
10-BIT OUTPUT
COMPARE REGISTER B
10-BIT OUTPUT
COMPARE REGISTER C
10-BIT OUTPUT
COMPARE REGISTER D
10-BIT OUTPUT
COMPARE REGISTER A
CLEAR
COUNT
CLK
T/C CONTROL
REGISTER C (TCCR1D)
FAULT_PROTECTION
W
GM10
FPIE1
FPF1
OC1OE5
OC1OE4
OC1OE3
OC1OE2
OC1OE1
OC1OE0
FPIE1
FPF1