am79c961 Advanced Micro Devices, am79c961 Datasheet - Page 171

• Manufacturer Part Number: am79c961
• Description: Pcnettm-isa Jumperless Single-chip Ethernet Controller For Isa
• Manufacturer: Advanced Micro Devices

Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
Descriptor
#9
#8
#7
#6
#5
#4
#3
#2
#1
SIZE = HEADER_SIZE (minimum 64 bytes)
OWN = 0
OWN = 1
OWN = 1
OWN = 0
OWN = 1
OWN = 1
OWN = 0
OWN = 1
OWN = 1
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
SIZE = S1+S2+S3+S4
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
SIZE = S1+S2+S3+S4
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
SIZE = S1+S2+S3+S4
SIZE = HEADER_SIZE (minimum 64 bytes)
SIZE = HEADER_SIZE (minimum 64 bytes)
Figure 4. LAPP 3 Buffer Grouping for TWO-INTERRUPT Method
STP = 0
STP = 0
STP = 1
STP = 0
STP = 0
STP = 1
STP = 0
STP = 0
STP = 1
Am79C961
Note that the times needed for tasks S1, S2, S3,
S4, and S6 should be divided by 0.8 ms to yield
an equivalent number of network byte times
before subtracting these quantities from the
expected message size A.
A
S1 = Interrupt latency
S2 = Application call latency
S3 =Time needed for driver to write
S4 = Time needed for driver to copy
S6 = Time needed for driver to copy
Note that the times needed for tasks S1,
S2, S3, S4, and S6 should be divided by
0.8 microseconds to yield an equivalent
number of network byte times before
subtracting these quantities from the
expected message size A.
= Expected message size in bytes
to third descriptor
data from buffer #1 to
data from buffer #2 to
application buffer space
application buffer space
18183B-82
AMD
1-645