Fujitsu MB91F109 FR30 Hardware Manual page 424

APPENDIX D Notes on Using Little Endian Areas
/* 32-bit data is accessed with a ST (or LD) instruction.*/
ST
/* 16-bit data is accessed with a STH (or LDH) instruction. */
STH
/* 8-bit data is accessed with a STB (or LDB) instruction. */
STB
If the MB91F109 accesses data with an operation for of a different size, the data value cannot
be guaranteed. For example, when two consecutive 16-bit data areas are simultaneously
accessed using a 32-bit access instruction, the data values cannot be assured.
400
r0, @r1
r2, @r3
r4, @r5