Actually, only PSIZE must be changed, because:
(chap. 9.5.5. of RM0383)In direct mode, MSIZE is forced by hardware to the same value as PSIZE as soon as bit EN = '1'.
(chap. 9.5.5. of RM0383)In direct mode, MSIZE is forced by hardware to the same value as PSIZE as soon as bit EN = '1'.