W5500 PHY link status reading PHYCFGR problem

Question

Hello, I’m using the W5500-EVB-Pico module. LwIP and c. At the very start of my code, immediatley after wizhip_initialize() I try and detect if the PHY link is up by reading bit 0 of the 5500 PHYCFGR register. My problem is if the code starts with no physical link (RJ45 jack is unplugged) it appears that getPHYCFGR() never returns and the program hangs. As soon as an RJ45 cable is plugged in the code starts to run as expected, even when the cable is subsequently un-plugged again. (The W5500 initialize code is based upon any Wiznet RP2040-HAT-LWIP-C refernce code) int main() { set_clock_khz(); stdio_init_all(); printf(“Hello from Main
”); wizchip_spi_initialize(); wizchip_cris_initialize(); wizchip_reset(); sleep_ms(200); wizchip_initialize(); // Check RJ45 plugged in! Registers specific to Wizchip W5500 // Non blocking 1 second loop while (connected == 0){ time_now = to_ms_since_boot(get_absolute_time()); if (time_now - time_then >= 1000){ time_then = time_now; if ((getPHYCFGR() & PHY_LINK_ON) != 0){ connected = 1; } printf(“************* Awaiting Ethernet PHY Up ****
"); } } printf(" Ethernet PHY Up *****************
”); wizchip_check(); code continues… So I’m expecting the code above to print “Awaiting Ethernet PHY Up” every second until the RJ45 is connected. In reality I get nothing until the RJ45 is connected. Can someone point out the error in my ways please? Thank you.

Eugeny · Answer

Format code properly. And it has nothing to do with W5500. It is purely C exercise.