UPD78361A Datasheet, PDF (20/88 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCONTROLLER

µPD78361A, 78362A
2.3.3 Special Function Registers (SFR)
Special function registers (SFRs) are registers assigned special functions such as mode registers and control
registers for internal peripheral hardware, and are mapped to a 256-byte address space at FF00H through
FFFFH.
Table 2-1 lists the SFRs. The meanings of the symbols in this table are as follows:
• Symbol ................................... Indicates the mnemonic symbol for an SFR.
This mnemonic can be coded in the operand field of an instruction.
• R/W ........................................ Indicates whether the SFR can be read or written.
R/W : Read/write
R : Read only
W : Write only
• Bit units for manipulation ...... Indicates bit units in which the SFR can be manipulated. The SFRs that
can be manipulated in 16-bit units can be coded as an sfrp operand.
Specify an even address for these SFRs.
The SFRs that can be manipulated in 1-bit units can be coded as the
operand of bit manipulation instructions.
• On reset ................................. Indicates the status of the register at RESET input.
Cautions 1. Do not access the addresses in the range FF00H-FFFFH to which no special function
register is allocated. If these addresses are accessed, malfunctio ning may occur.
2. Do not write data to the read-only registers. Otherwise, the internal circuit may not
operate normally.
3. When using read data as byte data, process undefined bit(s) first.
4. TOUT and TXS are write-only registers. Do no read these registers.
5. Bits 0, 1, and 4 of SBIC are write-only bits. When these bits are read, they are always
"0".
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