ch32v208_sens/README.md

lwIP Ethernet Driver for CH32V208

This is a simple ethernetif.c driver to get lwIP working on the WCH CH32V208 MCU using the ch32fun lib.
It uses the chip's internal 10Mbps Ethernet MAC. The MAC address is pulled from the chip's 6-byte unique ID.

The provided main.c is an example that starts up, gets an IP address via DHCP, and runs a small HTTP server.

Usage

1. Initialize lwIP and add the network interface.
2. Poll the driver and service lwIP's timers in your main loop.

netif_add(&g_netif, &ipaddr, &netmask, &gw, NULL, &ethernetif_init, &ethernet_input);
netif_set_default(&g_netif);
netif_set_up(&g_netif);
dhcp_start(&g_netif);

while (1) {
  // poll for incoming packets
  ethernetif_input(&g_netif);

  // handle lwIP timers (for TCP, DHCP, etc.)
  sys_check_timeouts();

  // poll link for link up/down cb
  ethernetif_link_poll(&g_netif);
}

seems okayish

$ wrk -t12 -c500 -d10s http://192.168.102.119
Running 10s test @ http://192.168.102.119
  12 threads and 500 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     1.87ms    6.98ms 613.62ms   99.63%
    Req/Sec   334.20    201.29     0.88k    74.58%
  8197 requests in 10.10s, 5.30MB read
Requests/sec:    811.63
Transfer/sec:    537.39KB

Impl note

This driver is kinda functional but not optimized

• Packet RX: This is done by polling RXIF works now. You must call ethernetif_input() continuously in your main loop to check for and process incoming packets
• Packet TX: TX isn't exactly typical DMA? The CPU has to copy the packet into a single transmit buffer and then manually start the transmission. An ISR will signal when the buffer is free to send the next packet