Note On Bit Manipulation Instructions - Hitachi H8S/2215 Series Hardware Manual

For four registers: ER0 to ER3
For the Hitachi H8S or H8/300 Series C/C++ Compiler, the STM/LDM instruction including ER7
is not created.
2.9.3

Note on Bit Manipulation Instructions

Bit manipulation instructions such as BSET, BCLR, BNOT, BST, and BIST read data in byte
units, perform bit manipulation, and write data in byte units. Thus, care must be taken when these
bit manipulation instruction are executed for a register or port including write-only bits.
In addition, the BCLR instruction can be used to clear the flag of the internal I/O register. In this
case, if the flag to be cleared has been set by an interrupt processing routine, the flag need not be
read before executing the BCLR instruction.
Rev. 3.0, 10/02, page 54 of 686