MC68HC908QL4 Datasheet, PDF (135/226 Pages) Motorola, Inc – Microcontrollers

Functional Description
14.3 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.
STATUS REGISTERS
LSVR AND LINIF _{SLCSVR CONTROL}
CONTROL REGISTERS
MESSAGE BUFFER — 9 BYTES
SLCID
SLCD7, SLCD6, SLCD5, SLCD4
SLCD3, SLCD2, SLCD1, SLCD0
LIN PROTOCOL STATE MACHINE
(PSM)
SHADOW REGISTER
1 BYTE
BUS CLOCK
SLIC CLOCK
DIGITAL RX FILTER
PRESCALER (RXFP[1:0])
DIGITAL RX FILTER
SLCRX
Figure 14-2. SLIC Module Block Diagram
SLCTX
MC68HC908QL4 Data Sheet, Rev. 7
Freescale Semiconductor
135