Technical information

3-9
Transmit Architecture
Type 3, 32-bit Addressing Mode (Frame Descriptor)
This mode is currently not supported in the AIC-6915.
Type 4, 32-bit Addressing Mode (Frame Descriptor)
Type 4 enables the driver to execute a simple and fast copy of DOS and OS2 data structure
(given by the upper layer software as a frame descriptor) to the descriptor queue area. The
only difference is the location of ‘Buffer Length’ and ‘Buffer Address’.
Table 3-5. Type 2 Transmit DMA Descriptor (64-bit Addressing)
31 24 23 16 15 8 7 0
Skip Field (multiple of 8 bytes)
One Skip Field per Buffer
ID =
4’b1011
I
N
T
R
E
N
D
C
A
L
T
C
P
C
R
C
E
N
Number Of Tx Buffers
(valid only if first
fragment)
Length (bytes)
Reserved
Low Address
High Address