Fujitsu FR81S Manuel D’Utilisation
MB91520 Series
FUJITSU SEMICONDUCTOR LIMITED
FUJITSU SEMICONDUCTOR CONFIDENTIAL
viii
Meaning of Bit Attribute Symbols
R
: Read enabled
W
: Write enabled
RM
: Reading operation during read-modify-write(RMW) operation
"/" (slash) R/W
: Read and write enabled. (The read value is the written value.)
"," (comma) R, W
: The read and written values differ from each other. (The read value is different
from the written value.)
from the written value.)
R0
: The read value is "0".
R1
: The read value is "1".
W0
: This bit must always be written to "0".
W1
: This bit must always be written to "1".
(RM0)
: "0" is read by read-modify-write(RMW) operation.
(RM1)
: "1" is read by read-modify-write(RMW) operation.
RX
: The read value is undefined. (A reserved bit or an undefined bit)
WX
: Writing does not affect on the operation. (Undefined bit)
• R/W writing examples
• R/W
: Read and write enabled (The read value is the written value.)
• R,W
: Read and write enabled (The read value is different from the written value.)
• R,RM/W : Read and write enabled (The read value is different from the written value. The written
value is read by read-modify-write (RMW) instruction. ) An example is a port data register.
• R(RM1),W : Read and write enabled (The read value is different from the written value. For
read-modify-write (RMW) instructions, "1" will be read out. ) An example is an interrupt
request flag.
request flag.
• R,WX
: Read only (Read enabled. Writing has no effect on operation. )
• R1,W
: Write only (Write enabled. The read value is "1".)
• R0,W
: Write only (Write enabled. The read value is "0".)
• RX,W
: Write only (Write enabled. The read value is undefined. )
• R0,W0
: Reserved bit (The written value is "0". The read value is the written value.)
• R0,W0
: Reserved bit (The written value is "0". The read value is "0".)
• R1,W0
: Reserved bit (The written value is "0". The read value is "1".)
• RX,W0
: Reserved bit (The written value is "0". The read value is undefined. )
• R/W1
: Reserved bit (The written value is "1". The read value is the written value.)
• R1,W1
: Reserved bit (The written value is "1". The read value is "1".)
• R0,W1
: Reserved bit (The written value is "1". The read value is "0".)
• RX,W1
: Reserved bit (The written value is "1". The read value is undefined. )
• RX,WX
: Undefined bit (The read value is undefined. Writing has no effect on operation.)
• R0,WX
: Undefined bit (The read value is "0". Writing has no effect on operation.)
MN705-00010-1v0-E
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