Hitachi H8/329 Series Hardware Manual page 53

Table 3-8. Bit-Manipulation Instructions (2)
Instruction Size*
B
BIXOR
B
BLD
BILD
B
BST
BIST
Note: * Size: operand size
B: Byte
Notes on Bit Manipulation Instructions: BSET, BCLR, BNOT, BST, and BIST are read-modify-
write instructions. They read a byte of data, modify one bit in the byte, then write the byte back.
Care is required when these instructions are applied to registers with write-only bits and to the I/O
port registers.
Step Description
1 Read Read one data byte at the specified address
2 Modify Modify one bit in the data byte
3 Write Write the modified data byte back to the specified address
Example: BCLR is executed to clear bit 0 in the port 4 data direction register (P4DDR) under the
following conditions.
P4 : Input pin, Low
7
P4 : Input pin, High
6
P4 – P4 : Output pins, Low
5 0
The intended purpose of this BCLR instruction is to switch P4
Function
C ⊕ ¬ [(<bit-No.> of <EAd>)] → C
XORs the C flag with the inverse of a specified bit in a general register
or memory.
The bit number is specified by 3-bit immediate data.
(<bit-No.> of <EAd>) → C
Copies a specified bit in a general register or memory to the C flag.
¬ (<bit-No.> of <EAd>) → C
Copies the inverse of a specified bit in a general register or memory to
the C flag.
The bit number is specified by 3-bit immediate data.
C → (<bit-No.> of <EAd>)
Copies the C flag to a specified bit in a general register or memory.
¬ C → (<bit-No.> of <EAd>)
Copies the inverse of the C flag to a specified bit in a general register or
memory.
The bit number is specified by 3-bit immediate data.
44
from output to input.
0