HD6413008F RENESAS [Renesas Technology Corp], HD6413008F Datasheet - Page 83

• Manufacturer Part Number: HD6413008F
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
• Manufacturer: RENESAS [Renesas Technology Corp]

2.6.5
The BSET, BCLR, BNOT, BST, and BIST instructions read a byte of data, modify a bit in the
byte, then write the byte back. Care is required when these instructions are used to access registers
with write-only bits, or to access ports.
Step
1
2
3
Example 1: BCLR is executed to clear bit 0 in the port 4 data direction register (P4DDR) under
the following conditions.
P4
P4
The intended purpose of this BCLR instruction is to switch P4
Operation field only
Operation field and register fields
Operation field, register fields, and effective address extension
Operation field, effective address extension, and condition field
7
5
, P4
– P4
6
:
Read
Modify
Write
0
op
:
Notes on Use of Bit Manipulation Instructions
Input pins
Output pins
op
op
Description
Read one data byte at the specified address
Modify one bit in the data byte
Write the modified data byte back to the specified address
cc
EA (disp)
Figure 2.9 Instruction Formats
op
rn
rn
EA (disp)
Rev.4.00 Aug. 20, 2007 Page 39 of 638
rm
rm
0
from output to input.
NOP, RTS, etc.
ADD.B Rn, Rm, etc.
MOV.B @(d:16, Rn), Rm
BRA d:8
REJ09B0395-0400
2. CPU