C8051F50x-F51x
Table 21.3. Autobaud Parameters Examples
System Clock (MHz)
Prescaler
Divider
312
25
24.5
24
1
1
1
1
1
0
0
0
0
306
300
22.1184
16
276
200
12.25
12
306
300
11.0592
8
276
200
21.3. LIN Master Mode Operation
The master node is responsible for the scheduling of messages and sends the header of each frame con-
taining the SYNCH BREAK FIELD, SYNCH FIELD, and IDENTIFIER FIELD. The steps to schedule a mes-
sage transmission or reception are listed below.
1. Load the 6-bit Identifier into the LIN0ID register.
2. Load the data length into the LIN0SIZE register. Set the value to the number of data bytes or "1111b" if
the data length should be decoded from the identifier. Also, set the checksum type, classic or
enhanced, in the same LIN0SIZE register.
3. Set the data direction by setting the TXRX bit (LIN0CTRL.5). Set the bit to 1 to perform a master
transmit operation, or set the bit to 0 to perform a master receive operation.
4. If performing a master transmit operation, load the data bytes to transmit into the data buffer (LIN0DT1
to LIN0DT8).
5. Set the STREQ bit (LIN0CTRL.0) to start the message transfer. The LIN controller will schedule the
message frame and request an interrupt if the message transfer is successfully completed or if an error
has occurred.
This code segment shows the procedure to schedule a message in a transmission operation:
LIN0ADR
= 0x08;
// Point to LIN0CTRL
LIN0DAT |= 0x20;
// Select to transmit data
// Point to LIN0ID
// Load the ID, in this example 0x11
// Point to LIN0SIZE
LIN0ADR
LIN0DAT
LIN0ADR
= 0x0E;
= 0x11;
= 0x0B;
LIN0DAT = ( LIN0DAT & 0xF0 ) | 0x08;
// Load the size with 8
LIN0ADR = 0x00;
for (i=0; i<8; i++)
{
// Point to Data buffer first byte
LIN0DAT = i + 0x41;
LIN0ADR++;
// Load the buffer with ‘A’, ‘B’, ...
// Increment the address to the next buffer
}
LIN0ADR = 0x08;
LIN0DAT = 0x01;
// Point to LIN0CTRL
// Start Request
The application should perform the following steps when an interrupt is requested.
1. Check the DONE bit (LIN0ST.0) and the ERROR bit (LIN0ST.2).
2. If performing a master receive operation and the transfer was successful, read the received data from
the data buffer.
Rev. 1.1
205
SILICON [ SILICON ]
