UPD784044 Datasheet, PDF (23/90 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLER

µPD784044(A), 784046(A)
6.2.3 Special function registers (SFRs)
The special function registers are registers to which special functions are assigned, and include the mode
registers and control registers of the internal peripheral hardware. These registers are mapped to a 256-byte
space of addresses 0FF00H through 0FFFFH^Note.
Note When the LOCATION 0 instruction is executed. FFF00H through FFFFFH when the LOCATION 0FH
instruction is executed.
Caution
Do not access an address in this area to which no SFR is allocated. If an address to which no
SFR is allocated is accessed by mistake, the µPD784046(A) may be deadlocked. The deadlock
status can be cleared only by inputting the reset signal.
Table 6-1 lists the special function registers. The meanings of the symbols in this table are as follows:
• Symbol ................................. Symbol indicating an SFR. These symbols are reserved for an NEC’s assembler
(RA78K4). With a C compiler (CC78K4), they can be used as sfr variables by
using the #pragma sfr directive.
• R/W ...................................... Indicates whether the corresponding SFR can be read/written.
R/W : Read/write
R : Read only
W : Write only
• Bit units for manipulation .... Indicates bit units in which the corresponding SFR can be manipulated.
SFRs that can be manipulated in 16-bit units can be written as operand sfrp.
Specify the even addresses of these SFRs when specifying an address.
SFRs that can be manipulated bit-wise can be written in bit manipulation
instructions.
• On reset ............................... Indicates the status of each register when the RESET signal is input.
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