MRF24J40-I/ML Microchip Technology, MRF24J40-I/ML Datasheet - Page 104

• 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

To configure the MRF24J40 for Unslotted CSMA-CA
mode, clear SLOTTED (TXMCR 0x11<5>) bit = 0.
The macMinBE and macMaxCSMABackoff values in
the MRF24J40 are set to the IEEE 802.15.4 Standard
defaults. To program their values:
• macMinBE – Program MACMINBE (TXMCR
• macMaxCSMABackoff – Program CSMABF
FIGURE 3-7:
DS39776C-page 104
MRF24J40
0x11<4:3>) bits to a value between 0 and 3 (the
IEEE 802.15.4 Standard default is 3).
(TXMCR 0x11<2:0>) bits to a value between 0
and 5 (the IEEE 802.15.4 Standard default is 4).
MACMINBE (TXMCR 0x11<4:3>)
MACMINBE (TXMCR 0x11<4:3>)
BATLIFEXT (TXMCR 0x11<6>)
BATLIFEXT (TXMCR 0x11<6>)
CSMABF (TXMCR 0x11<2:0>)
CSMABF (TXMCR 0x11<2:0>)
macMaxCSMABackoffs
macMaxCSMABackoffs
Battery Life Extension
Battery Life Extension
macMinBE
macMinBE
SLOTTED CSMA-CA ALGORITHM
Delay for Random (2
CW = 2, NB = NB + 1, BE = min(BE+1, aMaxBE)
Delay for Random (2
CW = 2, NB = NB + 1, BE = min(BE+1, aMaxBE)
N
N
Perform CCA on Backoff Period Boundary
Perform CCA on Backoff Period Boundary
Locate for Backoff Period Boundary
Locate for Backoff Period Boundary
CCAFAIL (TXSTAT 0x24<5>)
NB > macMaxCSMABackoffs?
NB > macMaxCSMABackoffs?
CCAFAIL (TXSTAT 0x24<5>)
(Report Channel Access
(Report Channel Access
BE = macMinBE
BE = macMinBE
NB = 0, CW = 2
NB = 0, CW = 2
Channel Idle?
Channel Idle?
Microcontroller)
Battery Life
Battery Life
Extension?
Failure to Host
Extension?
Microcontroller)
Failure to Host
FAILURE
BE
BE
Start
Start
FAILURE
– 1) Unit Backoff Periods
– 1) Unit Backoff Periods
N
N
N
N
Y
Y
Preliminary
Y
Y
Y
Y
Section 7.5.1.3 “The CSMA-CA Algorithm” for more infor-
3.9.2
Figure 3-7 shows the slotted CSMA-CA algorithm. This
mode is used on a beacon-enabled network where the
backoff period boundaries of every device on the network
shall be aligned with the superframe slot boundaries of
the PAN coordinator. Refer to IEEE 802.15.4-2003,
mation.
Configuring the MRF24J40 for beacon-enabled
network operation is covered in Section 3.8.1
“Beacon-Enabled Network” .
BE = lesser(2, macMinBE)
BE = lesser(2, macMinBE)
SLOTTED CSMA-CA MODE
(Transmit Pending Packet)
(Transmit Pending Packet)
TXNSTAT (TXSTAT
TXNSTAT (TXSTAT
CW = CW – 1
CW = CW – 1
0x24<0>)
0x24<0>)
SUCCESS
SUCCESS
CW = 0?
CW = 0?
© 2010 Microchip Technology Inc.
Y
Y
N
N