HD6413008VF25 Datasheet, PDF (85/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

2. CPU
Operation field only
op
NOP, RTS, etc.
Operation field and register fields
op
rn
rm
ADD.B Rn, Rm, etc.
Operation field, register fields, and effective address extension
op
rn
rm
EA (disp)
MOV.B @(d:16, Rn), Rm
Operation field, effective address extension, and condition field
op
cc
EA (disp)
BRA d:8
Figure 2.9 Instruction Formats
2.6.5 Notes on Use of Bit Manipulation Instructions
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
Read
Modify
Write
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
Example 1: BCLR is executed to clear bit 0 in the port 4 data direction register (P4DDR) under
the following conditions.
P4₇, P4₆: Input pins
P4₅ – P4₀: Output pins
The intended purpose of this BCLR instruction is to switch P4₀ from output to input.
Rev.4.00 Aug. 20, 2007 Page 39 of 638
REJ09B0395-0400