HT82M75REW/HT82K75REW
Rev. 1.00
48
June 11, 2010
RF Transceiver Low MAC Block
The RF Transceiver MAC provides plenty of hard-
ware-assisted features to relieve the host MCU power
requirement. Besides providing reliable wireless packet
transactions between two nodes, it also handles data
and command transfer between the network and the
physical layers PHY.
MAC Frame Format
·
Data Frame
The address field contains the broadcast address
(0xFFFF-FFFFH) or destination address. The bit 0 of
frame control (FC) field is used for Ack-Request which
specifies whether an acknowledgement is required
from the recipient device. If the bit is
²
1
²
, the recipient
device shall send an acknowledgement frame back
after determining that the received frame is valid. The
bit 1 of FC field is
²
0
²
for data frame. The length of
payload field is variable from 0 to 56 bytes. The frame
check sequence (FCS) is calculated over the address
field, FC field and the payload. The polynomial is de-
gree 16:
·
Acknowledgement Frame
The length of acknowledgement frame is always 5
bytes. Bit 1 of FC field is 1 for ACK frame. The payload
field, containing user information of acknowledge-
ment frame, can be configured by SREG0x03 and
SREG0x04. The FCS is calculated over the FCS of
the received packet, FC field and the payload field.
The polynomial is degree 16:
Data Frame
Acknowledgement Frame
G ( x ) = x + x + x + 1
1 6
1 6
1 2
5
G ( x ) = x + x + x + 1
1 6
1 6
1 2
5
P H Y
L o w e r M A C
R X M A C
T X M A C
M e m o r y
I n t e r f a c i n g
Lower MAC Block Diagram
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