ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 232

• 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

17.7 Modes of Operation
17.7.1 Normal Mode
17.7.2 Clear Timer on Compare Match (CTC) Mode
232
ATmega128RFA1
The mode of operation i.e., the behavior of the Timer/Counter and the Output Compare
pins, is defined by the combination of the Waveform Generation mode (WGM02:0) and
Compare Output mode (COM0x1:0) bits. The Compare Output mode bits do not affect
the counting sequence while the Waveform Generation mode bits do. The COM0x1:0
bits control whether the PWM output generated should be inverted or not (inverted or
non-inverted PWM). For non-PWM modes the COM0x1:0 bits control whether the
output should be set, cleared, or toggled at a Compare Match (see
Unit" on page
For detailed timing information see
Table 17-5 shows the function of the WGM2:0 bits of registers TCCR0A and TCCR0B.
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 17-5. Waveform Generation Mode Bit Description
The simplest mode of operation is the Normal mode (WGM02:0 = 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 (TOV0) will be set at the same timer clock cycle when the TCNT0 becomes zero.
The TOV0 Flag in this case behaves like a 9
cleared. However, the timer resolution can be increased by software utilizing the timer
overflow interrupt that automatically clears the TOV0 Flag. There are no special cases
to consider in the Normal mode. A new counter value can be written at anytime.
The Output Compare Unit can be used to generate interrupts at some given time. It is
not recommended to use the Output Compare for waveform generation in Normal
mode, since this will occupy too much CPU time.
In Clear Timer on Compare (CTC) mode (WGM02:0 = 2), the OCR0A Register is used
to manipulate the counter resolution. In CTC mode the counter is cleared to zero when
the counter value (TCNT0) matches OCR0A. The OCR0A value defines the TOP value
Notes:
Mode
0
1
2
3
4
5
6
7
WGM2
0
0
0
0
1
1
1
1
228).
1. MAX = 0xFF
2. BOTTOM = 0x00
WGM1
0
0
1
1
0
0
1
1
WGM0
0
1
0
1
0
1
0
1
"Timer/Counter Timing Diagrams" on page
Timer/Counter
PWM, Phase
PWM, Phase
Operation
Fast PWM
Fast PWM
Reserved
Reserved
Mode of
Correct
Correct
Normal
CTC
th
bit, except that it is only set and not
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
–
–
Update of
Immediate
Immediate
BOTTOM
OCRX at
TOP
TOP
TOP
8266A-MCU Wireless-12/09
–
–
"Output Compare
TOV Flag
Set on
BOTTOM
BOTTOM
236.
MAX
MAX
MAX
TOP
–
–
(0,0)