User Manual

GAMMA instabus
Release: 12/2015
Application Program Bus Interface Modules M130, M131, M132 and M135
Runtime Environment for KNX-Processors 184/11 and 184/21
Technical Manual pages 17 Siemens AG
Building Technologies
Control Products and Systems
page 6 © Siemens AG 2015 P. O. Box 10 09 53,
Subject to change without further notice. D-93009 Regensburg
The switch between register sets is used to enhance performance. The four register sets are
used as follows:
 RB0: for user task
 RB1: for system task
 RB2: in all interrupt functions
 RB3: for flash firmware
The user application program must not modify the register select flags in the processor
status word!