OWN = 1
STP = 1
Descriptor
#1
SIZE = HEADER_SIZE (minimum 64 bytes)
OWN = 1
SIZE = S1+S2+S3+S4
STP = 0
A = Expected message size in bytes
S1 = Interrupt latency
S2 = Application call latency
S3 = Time needed for driver to write
to third descriptor
Descriptor
#2
OWN = 0
STP = 0
Descriptor
#3
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
S4 = Time needed for driver to copy
data from buffer #1 to
application buffer space
S6 = Time needed for driver to copy
data from buffer #2 to
OWN = 1 STP = 1
SIZE = HEADER_SIZE (minimum 64 bytes)
Descriptor
#4
OWN = 1
STP = 0
Descriptor
#5
SIZE = S1+S2+S3+S4
application buffer space
OWN = 0
STP = 0
Descriptor
#6
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
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.
OWN = 1 STP = 1
SIZE = HEADER_SIZE (minimum 64 bytes)
Descriptor
#7
OWN = 1
STP = 0
Descriptor
#8
SIZE = S1+S2+S3+S4
OWN = 0
STP = 0
Descriptor
#9
SIZE = 1518 - (S1+S2+S3+S4+HEADER_SIZE)
22206B-B4
Figure B-4. LAPP 3 Buffer Grouping for Two-interrupt Method
B-10
Am79C978
AMD [ AMD ]
