W7500 IAP and max clock speed

Question

Hi, I've made a small bootloader to allow W7500 update on a custom board without SWD or external probe. Sometimes, i have deadlock into IAP (never return from a call). I've made many tests, and finally try to re-write IAP and execute it into SRAM (to avoid delay into cpu fetch). Result is the same, CPU sometimes 'stop' when bit 16 of FACCR is set (0x00010000). During test, i've seen that when i reduce system frequency, i can drasticly reduce the number of errors (from 10% @ 20MHz to ~0% @ 8MHz) Is the Flash controller can work on the same frequency range than CPU ? Or, if there is a limit, what is the maximum frequency ? Best regards,

kralcllib · Answer

I have the same problem on W7500P. I have tried a 8 Mhz clock after my original 48Mhz with no observable difference. I am trying to load a large range of flash memory, single address at a time, and it crashes in the DO_IAP() after a few thousand calls. This is a critical problem that will prevent my company from using this mcu. I am using the WIZwiki-W7500P dev board. The provided “\W7500x_Library_Examples\Projects\Peripheral_Examples\Flash” example will also crash occasionally.

kralcllib · Answer

Hi Hooligan0, Thanks for the input. I wonder if this is a brown-out condition. I will forward your results to my EE. And, I will let you know if we come up with any new explanation. Thanks, Bill

kralcllib · Answer

I haven’t completely verified this solution, but to use IAP function to program flash, you must use the internal clock, not an external clock. I worked with an engineer at Wiznet, trading code back and forth, and was finally informed of this solution.