UPD784218 Datasheet, PDF (26/92 Pages) NEC – 16-/8-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784218, 784218Y
7.2.3 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 allocated. These registers are mapped to the 256-byte space
of addresses 0FF00H through 0FFFFH^Note.
Note On execution of the LOCATION 0H instruction. FFF00H through FFFFFH on execution of the LOCATION
0FH instruction.
Caution
Do not access an address in this area to which no SFR is allocated. If such an address is accessed
by mistake, the µPD784218 may enter a deadlock state. This deadlock state can be cleared only
by inputting the RESET signal.
Table 7-1 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 sfr variable by the #pragma sfr command with 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.
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Data Sheet U12304EJ2V0DS00