Data Sheet U14121EJ2V0DS00
31
μ
PD784214A, 784215A, 784216A, 784217A, 784218A, 784214AY, 784215AY, 784216AY, 784217AY, 784218AY
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6.2.3 Special function registers (SFRs)
The special function registers, such as the mode registers and control registers of the internal peripheral
hardware, are registers to which special functions are assigned. These registers are mapped to the 256-byte space
of addresses 0FF00H to 0FFFFH
Note
.
Note
On execution of the LOCATION 0H instruction. FFF00H to FFFFFH on execution of the LOCATION 0FH
instruction.
Caution Do not access an address in this area to which no SFR is assigned. If such an address is
accessed by mistake, the
μ
PD784218A may enter a deadlocked state. This deadlock state can be
cleared only by inputting the RESET signal.
Table 6-1 lists the special function registers (SFRs). The meanings of the symbols in this table are as follows.
Symbol ................................Symbol indicating an SFR. This symbol is reserved for NEC's assembler
(RA78K4). It can be used as an sfr variable by means of the #pragma sfr command
in the C compiler (CC78K4).
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.....Bit units in which the value of the SFR can be manipulated.
SFRs that can be manipulated in 16-bit units can be described as the operand sfrp
of an instruction. To specify the address of this SFR, describe an even address.
SFRs that can be manipulated in 1-bit units can be described as the operand of a
bit manipulation instruction.
After reset............................Indicates the status of the register when the RESET signal has been input.