Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Keil/AT32F407xx_v2/ETHERNET_MMC/MMCCTRL#0x0
Ethernet MMC control register
Reset counter
Stop counter rollover
Reset on read
Freeze MMC counter
https://github.com/cmsis-svd/cmsis-svd-data