Mitsubishi Electric MELSEC-Q Series User Manual page 190

10 DEVICES
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(c) Function registers
• Function registers are used to designate data transfers between the sub-
routine CALL source and the sub-routine program.
• The function register input/output condition is automatically determined by
the Basic model QCPU. If the sub-routine program data is the source data,
the data is designated as sub-routine input data.
If the sub-routine program data is the destination data, the data is
designated as sub-routine output data.
• 1 point occupies 4 words.
The number of words used depends on an instruction in a sub-routine
program.
A one-word instruction requires 1 word.
CALLP P0 D0
A two-work instruction requires 2 words.
CALLP P0 D0
The destination of 32-bit multiplication/division operation requires 4 words.
CALLP P0 D0
• Active devices cannot be used in a sub-routine program that contains
arguments. If devices assigned for function registers are used, values of the
function registers will not properly be returned to a calling program.
CALLP P0 D0
•Basic model QCPU's word data devices can be used.
REMARK
1) For a procedure for using function devices, see the QCPU (Q Mode)/QnACPU
Programming Manual (Common Instructions).
P0
The data is stored in one point (D0).
P0
The data is stored in two points (D0 and D1).
P0
The data is stored in four points (D0 to D3).
P0
Since the points (D0 to D3) are used
for FD0, D3 can not be used for the
sub-routine program.
MELSEC-Q
MOV R0 FD0
DMOV R0 FD0
D R0 R10 FD0
D R0 R10 FD0
MOV K0 D3
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