ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 313

• Manufacturer Part Number: ATMEGA128RFA1-ZU
• Description: IC AVR MCU 2.4GHZ XCEIVER 64QFN
• Manufacturer: Atmel
• Series: ATMEGAr

Specifications of ATMEGA128RFA1-ZU

• Frequency: 2.4GHz
• Data Rate - Maximum: 2Mbps
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: General Purpose
• Power - Output: 3.5dBm
• Sensitivity: -100dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 12.5mA
• Current - Transmitting: 14.5mA
• Data Interface: PCB, Surface Mount
• Memory Size: 128kB Flash, 4kB EEPROM, 16kB RAM
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN, Exposed Pad
• Rf Ic Case Style: QFN
• No. Of Pins: 64
• Supply Voltage Range: 1.8V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 16 KB
• Interface Type: JTAG
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 38
• Number Of Timers: 6
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVR128RFA1-EK1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

21.5.1 Normal Mode
21.5.2 Clear Timer on Compare Match (CTC) Mode
8266B-MCU Wireless-03/11
not (inverted or non-inverted PWM). For non-PWM modes the COM2x1:0 bits control
whether the output should be set, cleared, or toggled at a compare match (see chapter
"Compare Match Output Unit" on
For detailed timing information refer to chapter
page 320.
The following table shows the function of the WGM22:0 bits of registers TCCR2A and
TCCR2B. 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.
Table 21-2. Waveform Generation Mode Bit Description
The simplest mode of operation is the Normal mode (WGM22:0 = 0). In this mode the
counting direction is always up (incrementing), and no counter clear is performed. The
counter simply overruns when it passes its maximum 8 bit value (TOP = 0xFF) and then
restarts from the bottom (0x00). In normal operation the Timer/Counter Overflow Flag
(TOV2) will be set in the same timer clock cycle as the TCNT2 becomes zero. The
TOV2 Flag in this case behaves like a ninth bit, except that it is only set, not cleared.
However combined with the timer overflow interrupt that automatically clears the TOV2
Flag, the timer resolution can be increased by software. There are no special cases to
consider in the Normal mode, a new counter value can be written anytime.
The Output Compare unit can be used to generate interrupts at some given time. Using
the Output Compare to generate waveforms in Normal mode is not recommended,
since this will occupy too much of the CPU time.
In Clear Timer on Compare or CTC mode (WGM22:0 = 2), the OCR2A Register is used
to manipulate the counter resolution. In CTC mode the counter is cleared to zero when
the counter value (TCNT2) matches the OCR2A. The OCR2A defines the top value for
the counter, hence also its resolution. This mode allows greater control of the compare
match output frequency. It also simplifies the operation of counting external events.
The timing diagram for the CTC mode is shown in Table 20-3. The counter value
(TCNT2) increases until a compare match occurs between TCNT2 and OCR2A, and
then counter (TCNT2) is cleared.
Notes:
Mode
0
1
2
3
4
5
6
7
WGM2
0
0
0
0
1
1
1
1
1. MAX = 0xFF
2. BOTTOM = 0x00
WGM1
0
0
1
1
0
0
1
1
WGM0
0
1
0
1
0
1
0
1
page 318).
Timer/Counter
PWM, Phase
PWM, Phase
Operation
Fast PWM
Fast PWM
Reserved
Reserved
Mode of
Correct
Correct
Normal
CTC
"Timer/Counter Timing Diagrams" on
ATmega128RFA1
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
–
–
Update of
Immediate
Immediate
BOTTOM
OCRX at
TOP
TOP
TOP
–
–
TOV Flag
Set on
BOTTOM
BOTTOM
MAX
MAX
MAX
TOP
–
–
(1,2)
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