User's Manual

RTL8187L
Datasheet
Wireless LAN Network Interface Controller 22 Track ID JATR-1076-21 Rev. 1.2
11. Functional Description
11.1. Transmit & Receive Operations
The RTL8187L supports a new descriptor-based buffer management that will significantly lower host CPU utilization. The
RTL8187L supports transmit descriptor and receive descriptor in memory. Each OUT packet contains 3-double-word transmit
descriptors and each IN packet contains 4-double-word receive descriptors.
11.1.1. Transmit
Tx Descriptor Format
Table 27. Tx Descriptor Format
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
RSVD TXRATE
(4 bits)
R
T
S
E
N
RTSRATE
(4 bits)
C
T
S
E
N
M
O
R
E
F
R
A
G
S
P
L
C
P
N
O
_
E
N
C
R
Y
P
T
RSVD TPKTSIZE (12 bits) Offset 0
L
E
N
G
E
X
T
Length (15 bits) RTSDUR (16 bits) Offset 4
RATE_
FALL
BACK_
LIMIT
(4 bits)
R
S
V
D
(3 bits)
A
N
T
E
N
N
A
AGC (8 bits) RETRY_LIMIT (8 bits) CWMAX
(4 bits)
CWMIN
(4 bits)
Offset 8