Datasheet

Section 2 CPU
Rev. 4.00 Sep 27, 2006 page 82 of 1130
REJ09B0327-0400
2.10 Usage Note
2.10.1 TAS Instruction
Only register ER0, ER1, ER4, or ER5 should be used when using the TAS instruction. The TAS
instruction is not generated by the Renesas H8S and H8/300 series C/C++ compilers. If the TAS
instruction is used as a user-defined intrinsic function, ensure that only register ER0, ER1, ER4, or
ER5 is used.
2.10.2 STM/LDM Instruction
ER7 is not used as the register that can be saved (STM)/restored (LDM) when using STM/LDM
instruction, because ER7 is the stack pointer. Two, three, or four registers can be saved/restored by
one STM/LDM instruction. The following ranges can be specified in the register list.
Two registers: ER0—ER1, ER2—ER3, or ER4—ER5
Three registers: ER0—ER2, or ER4—ER6
Four registers: ER0—ER3
The STM/LDM instruction including ER7 is not generated by the Renesas H8S and H8/300 series
C/C++compilers.