Mitsubishi Q00JCPU User Manual page 508

9
DEVICE EXPLANATION
9.6.1 Switching between scan execution and low speed execution types
Basic
Note13
Note9.12
Redundant
The CPU module saves (protects) and restores the index register (Z0 to 15) contents
when switching between a scan execution type program and a low speed execution type
Note9.12
program.
(1) When switching from a scan execution type program to a low speed
(2) When switching from a low speed execution program to a scan
Execution program
Index register value
For scan execution
Index
type programs
register
storage
For low speed
area
execution type
program
Diagram 9.59 Saving and restoration of index register value at switching between scan and low speed execution type programs
(3) Exchanges of index register data
Note13
Redundant
Basic
Note9.12
9
9.6 Index Register (Z)
- 57
9.6.1 Switching between scan execution and low speed execution types
execution type program occurs.
The CPU module saves the index register value of the scan execution type program
and restores the index register value of the low speed execution type program.
execution type program occurs.
The CPU module saves the index register value of the low speed execution type
program and restores the index register value of the scan execution type program.
Switching
Scan execution
type program
Z0=1
Saved Reset
Z0=0 Z0=1
Z0=0 Z0=0
Word devices should be used for exchanges of index register data between scan
execution type programs and low speed execution type programs.
The Basic model QCPU and Redundant CPU cannot use low speed execution type programs.
When the Basic model QCPU or Redundant CPU is used, it is not necessary to be conscious of
the description in this section.
Switching
Low speed Scan execution
execution type type program
program
Z0=0 to Z0=3 1 Z0=1 to Z0=6
Saved Reset
Z0=1 Z0=1
Z0=0 Z0=3
1: For low-speed execution type program, Z0 is changed to 3.
2: For scan execution type program, Z0 is changed to 6.
Switching
Low speed
execution type
program
2
Saved Reset
Z0=1 Z0=6
Z0=3 Z0=3
Z0=3
Z0=6
Z0=3