Rainbow Electronics ATmega128RFA1 - Manual (Page 287)

287
8266A-MCU Wireless-12/09
ATmega128RFA1
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 RW R RW RW RW RW RW
Initial Value 0 0 0 0 0 0 0 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 – WGM41:40 - Waveform Generation Mode
Combined with the WGM41:0 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
0x0 Normal mode of operation
0x1 PWM, phase correct, 8-bit
0x2 PWM, phase correct, 9-bit
WGM41:40
0x3 PWM, phase correct, 10-bit