Why/When AICA abend happens in CICS region

Following content is copied from https://planetmainframe.com/2023/08/cics-programming-best-practices/

The option ICVR (Interval Control Value Runaway) is the amount of Task time that a task can consume between Calls to CICS. You see CICS is a very friendly system; it just says that you can freely use my services, you just have to talk to me once in a while. However, if you don’t talk to me, then I’m going to assume that you are looping and abend you. How does it do this? When you issue an EXEC CICS command and CICS processes your request, then control returns to your program. CICS then starts a Clock and decrements it while you have the CPU processing your COBOL/Assembler statements. If the Clock falls to zero, CICS, by Interval Control, will abend your task AICA.  Actually, it’s quite clever; it abends the Task with an S0C1 (Operation Exception). ICVR controls this Clock and it’s specified in the Overrides and changeable online by a CEMT SET SYSTEM command. 2000 milliseconds (2 seconds) is the default. This is a system-wide value but can be specified differently for each transaction.