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CPU Unit Operation Section 10-1
Parallel Processing (CJ1-H CPU Units Only)
The following two types of processing are performed in parallel in either of the
Parallel Processing Modes.
1,2,3... 1. Program execution: Includes user program execution and I/O refreshing. It
is this cycle time that is monitored from a Programming Device.
2. Peripheral servicing: Programming Devices and events from Special I/O
Units and CPU Bus Units are serviced when they occur.
There are two different Parallel Processing Modes. Parallel Processing with
Synchronous Memory Access refreshes I/O memory in the program execution
cycle and Parallel Processing with Asynchronous Memory Access refreshes
I/O memory in the peripheral servicing cycle.
Note Always disconnect the Programming Console from the peripheral port during
actual system operation in a Parallel Processing Mode. If the Programming
Console is left attached, excess time will be allocated to increase key
response for the Programming Console, adversely affecting performance.
Startup
initialization
I/O refreshing
(even in
PROGRAM
mode)
Peripheral
servicing
Program
execution
cycle
time
Initialize hardware
memory and system
work area.
Detect I/O.
Automatically transfer
data from Memory
Card.
Verify actual Units with
registered I/O tables.
Clear I/O memory.
Check user memory.
Clear forced status,
etc.
Program
execution
Operation processing: Execute the user
program.
Error processing: Turn OFF outputs.
(Reset Units for bus errors.)
After error: Clear I/O memory is an error
occurs (unless a FALS(007) instruction
created the error).
Refresh data for the following Units.
Basic I/O Units
Special I/O Units (both words allocated
in CIO and DM area and specific data
for each Unit)
CPU Bus Units (both words allocated in
CIO and DM area and specific data for
each Unit)
Perform the following servicing if any
events have occurred.
Special I/O Unit event servicing
CPU Bus Unit event servicing
Peripheral port servicing
RS-232C port servicing
Communications port servicing
Note: In Parallel Processing with
Synchronous Memory Access, any
events requiring I/O memory access
are serviced in the program execution
cycle.
Power ON
Read DIP switch settings.
Check I/O bus.
Overseeing
processing
Overseeing
processing
Program
Execution
Cycle
Peripheral
servicing
cycle time
Check the Battery.
Check I/O bus.
Check user program
memory.
Peripheral
servicing
Perform the following servicing if any events
have occurred.
File access servicing
Note: In Parallel Processing with Synchronous
Memory Access, any events requiring I/O
memory access are serviced here.
Note Refreshed in PROGRAM mode too.
Peripheral
Servicing
Cycle
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