MC9S08EL32 Datasheet, PDF (202/356 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

7
6
5
4
3
2
1
0
R
R7
R6
R5
R4
R3
R2
R1
R0
W
T7
T6
T5
T4
T3
T2
T1
T0
Reset
0
0
0
0
0
0
0
0
Figure 12-12. SLIC Data Register x (SLCD7–SLCD0)
R — Read SLC Receive Data
T — Write SLC Transmit Data
12.4 Functional Description
The SLIC provides full standard LIN message buffering for a slave node, minimizing the need for CPU
intervention. Routine protocol functions (such as synchronization to the communication channel,
reception, and verification of header data) and generation of the checksum are handled automatically by
the SLIC. This allows application software to be greatly simplified relative to standard UART
implementations, as well as reducing the impact of interrupts needed in those applications to handle each
byte of a message independently.
Additionally, the SLIC has the ability to automatically synchronize to any LIN message, regardless of the
LIN bus bit rate (1–20 kbps), properly receiving that message without prior programming of the target LIN
bit rate. Furthermore, this can even be accomplished using an untrimmed internal oscillator, provided its
accuracy is at least ±50% of nominal.
The SLIC also has a simple UART-like byte transfer mode, which allows the user to send and receive
single bytes of data in half-duplex 8-N-1 format (8-bit data, no parity, 1 stop bit) without the need for LIN
message framing.
12.5 Interrupts
The SLIC module contains one interrupt vector, which can be triggered by sources encoded in the SLIC
state vector register. See Section 12.3.5, “SLIC State Vector Register (SLCSV).”
12.5.1 SLIC During Break Interrupts
The BCFE bit in the BSCR register has no affect on the SLIC module. Therefore the SLIC modules status
bits cannot be protected during break.
12.6 Initialization/Application Information
The LIN specification defines a standard LIN “MESSAGE FRAME” as the basic format for transferring
data across a LIN network. A standard MESSAGE FRAME is composed as shown in Figure 12-13 (shown
with 8 data bytes).
LIN transmits all data, identifier, and checksum characters as standard UART characters with eight data
bits, no parity, and one stop bit. Therefore, each byte has a length of 10 bits, including the start and stop
bits. The data bits are transmitted least significant bit (LSB) first.
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
204
Freescale Semiconductor