Rainbow Electronics ATmega128RFA1 - Manual (Page 268)

268
8266A-MCU Wireless-12/09
ATmega128RFA1
Register Bits Value Description
0x2 PWM, phase correct, 9-bit
0x3 PWM, phase correct, 10-bit
0x4 CTC, TOP = OCRnA
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
18.11.2 TCCR1B – Timer/Counter1 Control Register B
Bit 7 6 5 4 3 2 1 0
NA ($81) ICNC1 ICES1 Res WGM13 WGM12 CS12 CS11 CS10 TCCR1B
Read/Write RW RW R RW RW RW RW RW
Initial Value 0 0 0 0 0 0 0 0
• Bit 7 – ICNC1 - Input Capture 1 Noise Canceller
Setting this bit (to one) activates the Input Capture Noise Canceler. When the Noise
Canceler is activated, the input from the Input Capture Pin (ICP1) is filtered. The filter
function requires four successive equal valued samples of the ICP1 pin for changing its
output. The input capture is therefore delayed by four Oscillator cycles when the noise
canceler is enabled.
• Bit 6 – ICES1 - Input Capture 1 Edge Select
This bit selects which edge on the Input Capture Pin (ICP1) that is used to trigger a
capture event. When the ICES1 bit is written to zero, a falling (negative) edge is used
as trigger. When the ICES1 bit is written to one, a rising (positive) edge will trigger the
capture. When a capture is triggered according to the ICES1 setting, the counter value
is copied into the Input Capture Register (ICR1). The event will also set the Input
Capture Flag (ICF1). This can be used to cause an Input Capture Interrupt, if this
interrupt is enabled. When the ICR1 is used as TOP value (see description of the
WGM13:0 bits located in the TCCR1A and the TCCR1B Register), the ICP1 is
disconnected and consequently the input capture function is disabled.
• 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 – WGM11:10 - Waveform Generation Mode