[U-Boot] ppc 85xx inline assembly

Hello, I am trying to understand the inline assembly function out_be32

extern inline void out_be32(volatile unsigned __iomem *addr, int val) { __asm__ __volatile__("sync; stw%U0%X0 %1,%0" : "=m" (*addr) : "r" (val)); }

I am not familiar with the syntax here, especially for the %U0%X0 part, can someone help me to translate this into assemble code?

Thanks Qingyu