MDK-ARM Keil, MDK-ARM Datasheet - Page 106

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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The tcp_get_state() function will return the current state of a socket. The
possible socket states are shown below:
On the first call, tcp_get_state() will report that the socket is closed. In this case,
we can open the socket for use and connect to a remote IP and port address.
if (TCPState == TCP_STATE_CLOSED)
}
Unlike UDP, we cannot simply prepare a packet of data and send it. Each TCP
frame is acknowledged by the remote station, so RL-TCPnet must hold each
frame in memory until it is acknowledged. If no acknowledgement arrives, then
the frame data must be available for re-sending. This requires careful
management. Obviously if we send lots of TCP frames, all of the
microcontroller RAM will be used up by TCP data waiting for an
acknowledgement. Before we can send a new frame, we must call
tcp_check_send(). This function ensures that the TCP connection is valid and
that the socket is not waiting for an earlier packet to be acknowledged.
If the socket is free, we can allocate a TCP data buffer and send a new packet in a
similar fashion to the UDP packets.
if (tcp_check_send (socket_tcp) == __TRUE)
}
tcp_connect (socket_tcp, Rem_IP, PORT_NUM, 0);
sendbuf = tcp_get_buf (SENDLEN);
tcp_send (socket_tcp, sendbuf, SENDLEN);
{
{
Chapter 4. RL-TCPnet Introduction