C-DIAS ANALOG INPUT MODULE
CAI 042
02.08.2011 Page
13
Communication (CDIAS)
Over the C-DIAS bus, the operating parameters and data can be read and written. Up to
256, 8-bit addresses can be accessed. The data transfer is divided it two register groups.
•
Status, instruction and configuration registers.
•
Data registers
Note:
Registers not mentioned below cannot be used as they are used by the CAI042
internally.
Remarque:
Registres exploités par la CAI042 en interne ne sont pas mentionnés ci-dessous et
ne peuvent pas être utilisés.
Data over the hardware can be read from the serial EEProm (LASAL EEProm) can be read.
Status, instruction and configuration registers
These registers can be addressed directly.
Data registers
To avoid bus conflicts between the controller and C-DIAS bus with 32-bit data transfers, the
data are stored in 2 pages. A flag in STATUSR always points to the page with the most
current values.
Process for Reading Data from the C-DIAS Bus
The control reads the PAGE bit in STATUSR. If this bit is cleared, the current data is stored
in PAGE0. If the bit is set, the current data is in PAGE1. Data can be read from the actual
page.
Process for Writing Data from the CAI 042 µC
The µC reads the PAGE bit in STATUSR. If it is cleared, the data is written to PAGE1. If the
PAGE bit is set, the data is written to PAGE0. The PAGE BIT is then inverted.
