A-3-2 Cpu Unit Behavior - Omron CP1L CPU Getting Started Manual

A-3-2 CPU Unit Behavior

This section briefly explains operations that take place within a CP1L CPU unit.
CPU Unit Operation Flow
Program executions (execution of instructions) are first processed, followed by I/O
refresh and execution of the peripheral servicing. These processes are repeated in
cyclic fashion.
Cycle
time
Power ON
· Initialize hardware memory and system work.
Power ON
(initialization)
· Detect connected units.
processes
· Execute automatic start-up transfer
from memory cassette.
· Clear I/O memory.
· Check user memory (UM).
· Force-set/force-reset.
Overseeing · Check for battery error.
processes
· Monitor DIP switches.
· Check I/O bus.
· Check user program memory.
Program
· During execution: Execute user program.
execution
· Error processing: Turn outputs OFF
(For bus errors, reset unit)
· When an error occurs: Clear I/O memory area
(except when executing FALS instructions)
I/O refresh Perform cyclic data exchange on the following units:
*
CP-series expansion I/O units
*I/O refresh is performed in PROGRAM mode also.
Peripheral Services only executed on event occurrence:
services
· Peripheral USB port service
· Serial port service
· Communication port service
· Built-in flash memory access service
· Memory cassette access service
· Online editing
A-3 Inner Workings of CP1L
SYSMAC CP1L Getting Started Guide
A
107