UPD78F0138 NEC, UPD78F0138 Datasheet - Page 73

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

3.2.3 Special Function Registers (SFRs)
manipulation instructions. The manipulatable bit units, 1, 8, and 16, depend on the special function register type.
Unlike a general-purpose register, each special function register has a special function.
SFRs are allocated to the FF00H to FFFFH area.
Special function registers can be manipulated like general-purpose registers, using operation, transfer and bit
Each manipulation bit unit can be specified as follows.
• 1-bit manipulation
• 8-bit manipulation
• 16-bit manipulation
Table 3-6 gives a list of the special function registers. The meanings of items in the table are as follows.
• Symbol
• R/W
• Manipulatable bit units
• After reset
Describe the symbol reserved by the assembler for the 1-bit manipulation instruction operand (sfr.bit).
This manipulation can also be specified with an address.
Describe the symbol reserved by the assembler for the 8-bit manipulation instruction operand (sfr).
This manipulation can also be specified with an address.
Describe the symbol reserved by the assembler for the 16-bit manipulation instruction operand (sfrp).
When specifying an address, describe an even address.
Symbol indicating the address of a special function register. It is a reserved word in the RA78K0, and is defined
by the header file “sfrbit.h” in the CC78K0. When using the RA78K0, ID78K0-NS, ID78K0, or SM78K0, symbols
can be written as an instruction operand.
Indicates whether the corresponding special function register can be read or written.
R/W: Read/write enable
R:
W:
Indicates the manipulatable bit unit (1, 8, or 16). “−” indicates a bit unit for which manipulation is not possible.
Indicates each register status upon RESET input.
Read only
Write only
CHAPTER 3 CPU ARCHITECTURE
User’s Manual U16228EJ2V0UD
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