47 tccr5b - timer/counter5 control register b, Atmega128rfa1 – Rainbow Electronics ATmega128RFA1 User Manual
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8266A-MCU Wireless-12/09
ATmega128RFA1
Register Bits
Value
Description
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
18.11.47 TCCR5B – Timer/Counter5 Control Register B
Bit
7
6
5
4
3
2
1
0
NA ($121)
ICNC5
ICES5
Res
WGM53 WGM52
CS52
CS51
CS50
TCCR5B
Read/Write
RW
RW
R
RW
RW
RW
RW
RW
Initial Value
0
0
0
0
0
0
0
0
•
Bit 7 – ICNC5 - Input Capture 5 Noise Canceller
Timer/Counter5 has only limited functionality. It is not connected to any Input Capture
Pin. Therefore this bit has no meaningful function.
•
Bit 6 – ICES5 - Input Capture 5 Edge Select
Timer/Counter5 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 – WGM51:50 - Waveform Generation Mode
Combined with the WGM51:0 bits found in the TCCR5A 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/Counter5 has
only limited functionality. It cannot be connected to any I/O pin.
Table 18-28 WGM5 Register Bits
Register Bits
Value
Description
0x0
Normal mode of operation
0x1
PWM, phase correct, 8-bit
0x2
PWM, phase correct, 9-bit
0x3
PWM, phase correct, 10-bit
0x4
CTC, TOP = OCRnA
0x5
Fast PWM, 8-bit
WGM51:50
0x6
Fast PWM, 9-bit