Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 378

(c) Function register (FD)
• The function register is used for data writing or reading between a subroutine program and a calling
program.
• The CPU module auto-detects the input or output conditions of the function register.
Source data are input data of the subroutine program.
Destination data are output data from the subroutine program.
• The function register of one point can occupy up to four words.
Note that, however, the number of words used differs depending on the instruction in the subroutine
program.
1) A one-word instruction uses one word only.
2) Two-word instruction uses two words.
3) At a destination using 32-bit multiplication or division, four words are used.
• Word devices of the CPU module can be used.
In subroutine programs with argument passing, do not use any devices that are used by the function register.
If this occurs, function register values will not be normally passed to the calling program.
For use of function devices, refer to the following.
MELSEC-Q/L Programming Manual (Common Instruction)
376
CALLP P0 D0
P0
Data is stored in D0 (1 point).
CALLP P0 D0
P0
Data are stored in D0 and D1 (2 points).
CALLP P0 D0
P0
Data are stored in D0 to D3 (4 points).
CALLP P0 D0
D* R0 R10 FD0
P0
Since D0 to D3 are used for FD0,
D3 cannot be used in the
subroutine program.
MOV R0 FD0
DMOV R0 FD0
*
D R0 R10 FD0
MOV K0 D3