ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 150

• 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

11.4 Calibrated Internal RC Oscillator
150
ATmega128RFA1
To ensure sufficient startup time, the device issues an internal reset with a time-out
delay (t
"Power-on Reset" on page 178
delay (t
delay is set by the SUTx and CKSELx fuse bits. The selectable delays are shown in
Table 11-2
shown in section
Table 11-2. Number of Watchdog Oscillator Cycles
Main purpose of the delay is to keep the AVR in reset until it is supplied with a stable
V
delay longer than the DEVDD rise time. If this is not possible, an internal or external
Brown-Out Detection (BOD) circuit should be used. A BOD circuit will ensure sufficient
V
the time-out delay without utilizing a Brown-Out Detection circuit is not recommended.
The oscillator is required to oscillate for a minimum number of cycles before the clock is
considered stable. An internal ripple counter monitors the oscillator output clock, and
keeps the internal reset active for a given number of clock cycles. The reset is then
released and the device will start to execute. The recommended oscillator start-up time
is dependent on the clock type, and varies from 6 cycles for an externally applied clock
to 32K cycles for a low frequency crystal.
The start-up sequence for the clock includes both the time-out delay and the start-up
time when the device starts up from reset. When starting up from Power-save or Power-
down mode, DEVDD is assumed to be at a sufficient level and only the start-up time is
included.
By default, the Internal RC Oscillator provides an approximate 16 MHz clock. The RC
oscillator is voltage and temperature dependent, but can be very accurately calibrated
by the user. See chapter
Speed" on page 537
the 1:2 system clock prescaler programmed. See section
page 153
This clock may be selected as the system clock by programming the CKSEL Fuses as
shown in
components. During reset, hardware loads the pre-programmed calibration value into
the OSCCAL Register and thereby automatically calibrates the RC Oscillator. The
accuracy of this calibration is shown as Factory calibration in section
Characteristics" on page
By changing the OSCCAL register (see
page
using the factory calibration. The accuracy of this calibration is shown as User
calibration in section
Typ Time-out
0 ms
4.0 ms
64 ms
DEVDD
DEVDD
154) from Software, it is possible to get a higher calibration accuracy than by
. The delay will not monitor the actual voltage and it will be required to select a
before it releases the reset, and the time-out delay can be disabled. Disabling
TOUT
TOUT
for more details.
Table 11-3 on
) is timed from the Watchdog Oscillator and the number of cycles in the
) after the device reset is released by all other reset sources. Section
below. The frequency of the Watchdog Oscillator is voltage dependent as
"Typical Characteristics" on page
"Clock Characteristics" on page
for more details. The device is shipped with the CKDIV8 Fuse and
505.
"Clock Characteristics" on page 505
page 151. If selected, it will operate with no external
describes the start conditions for the internal reset. The
Number of Cycles
0
512
8K (8,192)
"OSCCAL – Oscillator Calibration Value" on
515.
505.
"System Clock Prescaler" on
and
8266B-MCU Wireless-03/11
"Internal Oscillator
"Clock