ATMEGA256RZAV-8AU Atmel, ATMEGA256RZAV-8AU Datasheet - Page 221

• Manufacturer Part Number: ATMEGA256RZAV-8AU
• Description: MCU ATMEGA2561/AT86RF230 64-TQFP
• Manufacturer: Atmel
• Series: ATMEGAr

Specifications of ATMEGA256RZAV-8AU

• Frequency: 2.4GHz
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: ISM, ZigBee™
• Power - Output: 3dBm
• Sensitivity: -101dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 15.5mA
• Current - Transmitting: 16.5mA
• Data Interface: PCB, Surface Mount
• Memory Size: 256kB Flash, 4kB EEPROM, 8kB RAM
• Antenna Connector: PCB, Surface Mount
• Package / Case: 64-TQFP
• Wireless Frequency: 2.4 GHz
• Interface Type: JTAG, SPI
• Output Power: 3 dBm
• For Use With: ATAVRISP2 - PROGRAMMER AVR IN SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Data Rate - Maximum: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: ATmega256

21.8
2549M–AVR–09/10
Multi-processor Communication Mode
Table 21-2
that Normal Speed mode has higher toleration of baud rate variations.
Table 21-2.
Table 21-3.
The recommendations of the maximum receiver baud rate error was made under the assump-
tion that the Receiver and Transmitter equally divides the maximum total error.
There are two possible sources for the receivers baud rate error. The Receiver’s system clock
(XTAL) will always have some minor instability over the supply voltage range and the tempera-
ture range. When using a crystal to generate the system clock, this is rarely a problem, but for a
resonator the system clock may differ more than 2% depending of the resonators tolerance. The
second source for the error is more controllable. The baud rate generator can not always do an
exact division of the system frequency to get the baud rate wanted. In this case an UBRR value
that gives an acceptable low error can be used if possible.
Setting the Multi-processor Communication mode (MPCMn) bit in UCSRnA enables a filtering
function of incoming frames received by the USART Receiver. Frames that do not contain
address information will be ignored and not put into the receive buffer. This effectively reduces
the number of incoming frames that has to be handled by the CPU, in a system with multiple
MCUs that communicate via the same serial bus. The Transmitter is unaffected by the MPCMn
setting, but has to be used differently when it is a part of a system utilizing the Multi-processor
Communication mode.
If the Receiver is set up to receive frames that contain 5 to 8 data bits, then the first stop bit indi-
cates if the frame contains data or address information. If the Receiver is set up for frames with
# (Data+Parity Bit)
# (Data+Parity Bit)
10
10
D
D
5
6
7
8
9
5
6
7
8
9
and
Recommended Maximum Receiver Baud Rate Error for Normal Speed Mode
(U2Xn = 0)
Recommended Maximum Receiver Baud Rate Error for Double Speed Mode
(U2Xn = 1)
Table 21-3
R
R
slow
slow
93.20
94.12
94.81
95.36
95.81
96.17
94.12
94.92
95.52
96.00
96.39
96.70
list the maximum receiver baud rate error that can be tolerated. Note
(%)
(%)
ATmega640/1280/1281/2560/2561
R
R
105.66
104.92
104.35
103.90
103.53
103.23
106.67
105.79
105.11
104.58
104.14
103.78
fast
fast
(%)
(%)
Max Total Error (%)
Max Total Error (%)
+5.66/-5.88
+4.92/-5.08
+4.35/-4.48
+3.90/-4.00
+3.53/-3.61
+3.23/-3.30
+5.79/-5.88
+5.11/-5.19
+4.58/-4.54
+4.14/-4.19
+3.78/-3.83
+6.67/-6.8
Recommended Max
Recommended Max
Receiver Error (%)
Receiver Error (%)
±2.5
±2.0
±1.5
±1.5
±1.5
±1.0
±3.0
±2.5
±2.0
±2.0
±1.5
±1.5
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