Cpu Unit Operation; General Flow - Omron CP1H CPU Operation Manual

CPU Unit Operation

2-4

CPU Unit Operation

2-4-1

General Flow

Cycle time
82
The following flowchart shows the overall operation of the CPU Unit. First the
user program is executed and then I/O is refreshed and peripheral servicing is
performed. These processes are then repeated in cyclic fashion.
Power ON
Startup
Initialize hardware
initialization
memory and system work
area.
Detect I/O.
Automatically transfer data
from Memory Cassette.
Overseeing
Check the Battery.
processing
Read DIP switch settings.
Check I/O bus.
Program
execution
Operation processing: Execute the user program.
Error processing: Turn OFF outputs. (Reset Units
for bus errors.)
After error: Clear I/O memory if an error occurs
(unless a FALS(007) instruction created the error).
I/O refreshing Refresh data for the following Units.
(even in
CP-series Expansion Units and Expansion I/O Units
PROGRAM
CJ-series Special I/O Units (both words allocated in CIO Area and
mode)
specific data for each Unit)
CJ-series CPU Bus Units (both words allocated in CIO and DM Areas
and specific data for each Unit)
Perform the following servicing if any events have occurred.
Peripheral
CJ-series Special I/O Unit event servicing
servicing
CJ-series CPU Bus Unit event servicing
Peripheral USB port servicing
Serial port servicing
Communications port servicing
Built-in flash memory access servicing
Memory Cassette access servicing
Clear I/O memory.
Check user memory.
Clear forced status, etc.
Check user program
memory.
Section 2-4