Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/ETH/ETH_MMC_FPE_TX_FCR#0x0
MMC FPE Tx fragment counter register
Tx FPE Fragment counter
https://github.com/modm-io/cmsis-svd-stm32