IBM nec pd78081(a) User Manual

Unlike a general register, each special-function register has special functions.

It is allocated in the FF00H to FFFFH area.

The special-function register can be manipulated like the general register, with the operation, transfer and bit

manipulation instructions.  Manipulatable bit units, 1, 8 and 16, depend on the special-function register type.

Each manipulation bit unit can be specified as follows.

• 1-bit manipulation

Describe the symbol reserved with assembler for the 1-bit manipulation instruction operand (sfr.bit).

This manipulation can also be specified with an address.

• 8-bit manipulation

Describe the symbol reserved with assembler for the 8-bit manipulation instruction operand (sfr).

This manipulation can also be specified with an address.

• 16-bit manipulation

Describe the symbol reserved with assembler for the 16-bit manipulation instruction operand (sfrp).

When addressing an address, describe an even address.

Table 3-2 gives a list of special-function registers.  The meaning of items in the table is as follows.

• Symbol

Symbols indicating the addresses of special function register.  These symbols are reserved words for the RA78K/

0 and defined by header file sfrbit.h for the CC78K/0, and can be used as the operands of instructions when

the RA78K/0, ID78K0, and SD78K/0 are used.

• R/W

Indicates whether the corresponding special-function register can be read or written.

R/W :  Read/write enable

R

:  Read only

W

:  Write only

• Manipulatable bit units

√

 indicates bit units (1, 8 or 16 bits) in which the register can be manipulated.  — indicates that the register cannot

be manipulated in the indicated bit units.

• After reset

Indicates each register status upon RESET input.