MRF24J40-I/ML Microchip Technology, MRF24J40-I/ML Datasheet - Page 103

• Manufacturer Part Number: MRF24J40-I/ML
• Description: IC TXRX IEEE/ZIGBEE 2.4GHZ 40QFN
• Manufacturer: Microchip Technology

Specifications of MRF24J40-I/ML

• Package / Case: 40-QFN
• Frequency: 2.4GHz
• Data Rate - Maximum: 250kbps
• Modulation Or Protocol: 802.15.4
• Applications: ISM, ZigBee™
• Power - Output: 0dBm
• Sensitivity: -95dBm
• Voltage - Supply: 2.4 V ~ 3.6 V
• Current - Receiving: 18mA
• Current - Transmitting: 18mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 1
• Number Of Transmitters: 1
• Wireless Frequency: 2.4 GHz
• Interface Type: 4 Wire SPI
• Noise Figure: 8 dB
• Output Power: + 0 dBm
• Operating Supply Voltage: 2.5 V, 3.3 V
• Maximum Operating Temperature: 85 C
• Mounting Style: SMD/SMT
• Maximum Supply Current: 22 mA
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.9
MRF24J40 supports both unslotted and slotted
CSMA-CA
IEEE 802.15.4
CSMA-CA algorithm is implemented using units of time
called backoff periods. In slotted CSMA-CA, the back-
off period boundaries of every device on the PAN shall
be aligned with the superframe slot boundaries of the
PAN coordinator. In unslotted CSMA-CA, the backoff
periods of one device are not related in time to the
backoff periods of any other device in the PAN. Refer to
FIGURE 3-6:
© 2010 Microchip Technology Inc.
CSMABF (TXMCR 0x11<2:0>)
Carrier Sense Multiple
Access-Collision Avoidance
(CSMA-CA) Algorithm
macMaxCSMABackoffs
mechanisms,
Standard.
UNSLOTTED CSMA-CA ALGORITHM
In
as
Delay for Random (2
NB = NB + 1, BE = min(BE + 1, aMaxBE)
N
both
defined
(Report Channel Access Failure
NB = 0, BE = macMinBE
macMaxCSMABackoffs
CCAFAIL (TXSTAT 0x24<5>)
modes,
to Host Microcontroller)
Channel Idle?
Perform CCA
in
NB >
Start
FAILURE
BE
Preliminary
the
the
– 1) Backoff Periods
N
Y
IEEE 802.15.4-2003, Section 7.5.1.3 “The CSMA-CA
Algorithm” for more information. This section covers
the two modes and their settings.
3.9.1
Figure 3-6 shows the unslotted CSMA-CA algorithm.
This mode is used in a nonbeacon-enabled network
where the backoff periods of one device are not related
in time to the backoff periods of any other device in the
network. Refer to IEEE 802.15.4-2003, Section 7.5.1.3
“The CSMA-CA Algorithm” for more information.
Configuring the MRF24J40 for nonbeacon-enabled
network operation is covered in Section 3.8.2
“Nonbeacon-Enabled Network” .
Note:
Y
TXNSTAT (TXSTAT 0x24<0>)
Acknowledgment and beacon frames are
sent
mechanism.
UNSLOTTED CSMA-CA MODE
(Transmit Pending Packet)
MACMINBE (TXMCR 0x11<4:3>)
without
SUCCESS
MRF24J40
macMinBE
using
DS39776C-page 103
a
CSMA-CA