Dear Liu Hui-R64343, [...]
> >> >> According to REV C manual, the register IOMUXC_IOMUXC_GPR4 has bits > >> >> 4 and 5 read-only and the value is always set as zero. > >> >> So write '0' to these bits instead of writing '1'. > >> > > >> >Jason, Fabio: What do you think? You should be the datasheet > >> >'masters' ;) > >> > >> Yes, according to the RM, > >> 5 > >> Reserved > >> This read-only field is reserved and always has the value 0. > >> 4 > >> Reserved > >> This read-only field is reserved and always has the value 0. > >> > >> So, write 1 should have no effect. > > > >I really dislike how "write 1 should have no effect" sounds. Can you > >please check with HW people? > > Since this is read-only bit, if you write 1 to it, it will have no effect. For how long do you work with hardware? Did it never occur to you that when you wrote 1 to an "reserved" bit, it either did something you didn't expect or you had to rework it later because the new CPU has that bit for something else? > Yes, to avoid the confusion, for example to do the read-back check, I agree > with not writing '1' to the read-only bit. Please, ask the hardware people about this. > >[..] > > > >Best regards, > >Marek Vasut Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot