![](http://datasheet.mmic.net.cn/370000/UPD784907_datasheet_16743927/UPD784907_27.png)
μ
PD784907, 784908
27
Data Sheet U11680EJ2V0DS00
7.2.3 Special function registers (SFRs)
The special function registers are registers with special functions such as mode registers and control registers for
built-in peripheral hardware. The special function registers are mapped onto the 256-byte space between 0FF00H
and 0FFFFH
Note
.
Note
On execution of the LOCATION 0 instruction. FFF00H to FFFFFH when the LOCATION 0FH instruction
is executed.
Caution
Do not access an address in this area where no SFR is allocated, as the
μ
PD784908 may be placed
in the deadlock state. The deadlock state can be cleared only by a reset.
Table 7-1 lists the special function registers (SFRs). The symbols of the table columns are explained below.
Symbol.................................... Symbol indicating an on-chip SFR. The symbols listed in the table are reserved
words for the NEC assembler (RA78K4). In the C compiler (CC78K4), the
symbols can be used as sfr variables with the #pragma sfr command.
R/W ......................................... Indicates whether the SFR is read-only, write-only, or read/write.
R/W: Read/write
R:
Read-only.
W:
Write-only.
Bit units for manipulation ....... Indicates the maximum number of bits that can be manipulated whenever an SFR
is manipulated. An SFR that supports 16-bit manipulation can be described in
the sfrp operand. For address specification, an even-numbered address must
be specified.
An SFR that can be manipulated in 1-bit units can be described as the operand
of a bit manipulation instruction.
After reset............................... Indicates the state of the register when the RESET signal has been input.