W3100A Datasheet, PDF (33/63 Pages) List of Unclassifed Manufacturers – i2Chip W3100A

port set prior to this transmission are different to the destination IP and port to be used for the transmission,
the values need to be updated before executing the send command.
UDP sendto
No
Yes
UDP starting point
UDP
Cx_TW_PR = A
Cx_TR_PR = A
cal FBS(free
buffer size)
FBS >
SDS(send
data size)
Yes
Send bit ==
'1'
FBS <=
Cx_TW_PR -
Cx_TR_PR
check previous
send comand
write data from
Cx_TW_PR
No
write data
Cx_TW_PR <= _{update Cx_TW_PR}
Cx_TW_PR + SDS
if need, update
DIP, DPort
send command
Pointer Management during UDP Transmission
CH3
CH2
CH1
0x2000 0x0800
0x1800
0x1000
0x0800
Cx_TW_PR and
Cx_TA_PR are
equal
(0x00123000
assumed)
0x0800
Cx_TW_PR is
increased to
0x00123200
(MCU)
Cx_TW_PR
0x0800
0x0200
0x0200
CH0
Tx
data
Cx_TR_PR
Cx_TR_PR is
increased to
0x0000 _0x0000
0x0000
0x0000
0x00123200
2KB allocated at Since transmission memory is
When MCU records the
When W3100A ^(W3100A)
each channel
2KB, mask is 0x000007FF transmission data for transmission ^{completes the}
and Cx_TW_PR is increased
transmission
Above diagram illustrates the change in Cx_TW_PR and Cx_TA_PR when actual data transmission is made
after 2KB of transmission memory is set at CH0.
UDP Data Reception
W3100A’s UDP reception is similar to TCP reception. The difference is that the header information for
UDP processing is included in the received data in addition to the data. The header is structured as below.
TLEN
SIP
SPort
0
2
4
6
8
UDP data
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