ATTINY26L8SU SL383 Atmel, ATTINY26L8SU SL383 Datasheet - Page 72

• Manufacturer Part Number: ATTINY26L8SU SL383
• Description: MCU 8-Bit ATtiny AVR RISC 2KB Flash 3.3V/5V 20-Pin SOIC T/R
• Manufacturer: Atmel

Timer/Counter1 Control
Register A – TCCR1A
72
ATtiny26(L)
• Bits 7, 6 – COM1A1, COM1A0: Comparator A Output Mode, Bits 1 and 0
The COM1A1 and COM1A0 control bits determine any output pin action following a
Compare Match with Compare Register A in Timer/Counter1. Output pin actions affect
pin PB1 (OC1A). Since this is an alternative function to an I/O port, the corresponding
direction control bit must be set (one) in order to control an output pin. Note that OC1A is
not connected in normal mode.
Table 32. Comparator A Mode Select
In PWM mode, these bits have different functions. Refer to Table 35 on page 77 for a
detailed description.
• Bits 5, 4 – COM1B1, COM1B0: Comparator B Output Mode, Bits 1 and 0
The COM1B1 and COM1B0 control bits determine any output pin action following a
Compare Match with Compare Register B in Timer/Counter1. Output pin actions affect
pin PB3 (OC1B). Since this is an alternative function to an I/O port, the corresponding
direction control bit must be set (one) in order to control an output pin. Note that OC1B is
not connected in normal mode.
Table 33. Comparator B Mode Select
In PWM mode, these bits have different functions. Refer to Table 35 on page 77 for a
detailed description.
• Bit 3 – FOC1A: Force Output Compare Match 1A
Writing a logical one to this bit forces a change in the Compare Match output pin PB1
(OC1A) according to the values already set in COM1A1 and COM1A0. If COM1A1 and
COM1A0 written in the same cycle as FOC1A, the new settings will be used. The Force
Output Compare bit can be used to change the output pin value regardless of the timer
value. The automatic action programmed in COM1A1 and COM1A0 takes place as if a
compare match had occurred, but no interrupt is generated. The FOC1A bit always
reads as zero. FOC1A is not in use if PWM1A bit is set.
• Bit 2 – FOC1B: Force Output Compare Match 1B
Bit
$30 ($50)
Read/Write
Initial Value
COM1A1
COM1B1
0
0
1
1
0
0
1
1
COM1A1
COM1A0
COM1B0
R/W
7
0
0
1
0
1
0
1
0
1
COM1A0
R/W
6
0
Description
Timer/Counter Comparator A disconnected from output pin OC1A.
Toggle the OC1A output line.
Clear the OC1A output line.
Set the OC1A output line.
Description
Timer/Counter Comparator B disconnected from output pin OC1B.
Toggle the OC1B output line.
Clear the OC1B output line.
Set the OC1B output line.
COM1B1
R/W
5
0
COM1B0
R/W
4
0
FOC1A
R/W
3
0
FOC1B
R/W
2
0
PWM1A
R/W
1
0
PWM1B
R/W
1477J–AVR–06/07
0
0
TCCR1A