
317
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
Register Bits
Value
Description
0x5
Fast PWM, 8-bit
0x6
Fast PWM, 9-bit
0x7
Fast PWM, 10-bit
0x8
PWM, Phase and frequency correct, TOP =
ICRn
0x9
PWM, Phase and frequency correct, TOP =
OCRnA
0xA
PWM, Phase correct, TOP = ICRn
0xB
PWM, Phase correct, TOP = OCRnA
0xC
CTC, TOP = OCRnA
0xD
Reserved
0xE
Fast PWM, TOP = ICRn
0xF
Fast PWM, TOP = OCRnA
18.11.32 TCCR4B – Timer/Counter4 Control Register B
Bit
7
6
5
4
3
2
1
0
NA ($A1)
ICNC4
ICES4
Res
WGM43
WGM42
CS42
CS41
CS40
TCCR4B
Read/Write
RW
R
RW
Initial Value
0
Bit 7 – ICNC4 - Input Capture 4 Noise Canceller
Timer/Counter4 has only limited functionality. It is not connected to any Input Capture
Pin. Therefore this bit has no meaningful function.
Bit 6 – ICES4 - Input Capture 4 Edge Select
Timer/Counter4 has only limited functionality. It is not connected to any Input Capture
Pin. Therefore this bit has no meaningful function.
Bit 5 – Res - Reserved Bit
This bit is reserved for future use. A read access always will return zero. A write access
does not modify the content.
Bit 4:3 – WGM43:42 - Waveform Generation Mode
Combined with the WGM41:40 bits, found in the TCCR4A Register, these bits control
the counting sequence of the counter, the source for maximum (TOP) counter value
and what type of waveform generation to be used. Modes of operation supported by the
Timer/Counter unit are: Normal mode (counter), Clear Timer on Compare match (CTC)
mode, and three types of Pulse Width Modulation (PWM) modes. For more information
on the different modes see section "Modes of Operation". Note that Timer/Counter4 has
only limited functionality. It cannot be connected to any I/O pin.
Table 18-22 WGM4 Register Bits
Register Bits
Value
Description
WGM43:40
0x0
Normal mode of operation
0x1
PWM, phase correct, 8-bit
0x2
PWM, phase correct, 9-bit
0x3
PWM, phase correct, 10-bit