C515C_9711 Datasheet, PDF (174/268 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C515C
6.5.10Configuration Examples of a Reception Object
The microcontroller wishes to configure an object for reception. It wishes to receive an interrupt
each time new data comes in. From time to time the microcontroller sends a remote request to
trigger the sending of this data from a remote node.
Initialization: The identifier and direction are set up.
Message Control Register
Bit No. MSB
7
6
5
4
3
2
1
0
0
1
1
0
MSGVAL
TXIE
RXIE
0
1
RMTPND
0
1
TXRQ
0
1
MSGLST
LSB
1
0
0
1
MCR0
INTPND
0
1
NEWDAT
MCR1
Configuration after reception of data.
Message Control Register
Bit No. MSB
7
6
5
4
1
0
0
1
MSGVAL
TXIE
0
1
RMTPND
0
1
TXRQ
3
2
1
0
RXIE
0
1
MSGLST
LSB
1
0
1
0
MCR0
INTPND
1
0
NEWDAT
MCR1
To process the message the microcontroller should clear IntPnd, clear NewDat, process the data,
and check that NewDat is still clear. If not, it should repeat the process again. To send a remote
frame to request the data, the microcontroller simply needs to set the TXRQ bit. This bit will be
cleared by the CAN controller, once the remote frame has been sent or if the data is received before
the CAN controller could transmit the remote frame.
Semiconductor Group
6-111
1997-11-01