MC908QL4MDWE Freescale Semiconductor, MC908QL4MDWE Datasheet - Page 150

• Manufacturer Part Number: MC908QL4MDWE
• Description: IC MCU 8BIT 4K FLASH 16-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908QL4MDWE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: LIN (Local Interconnect Network)
• Peripherals: LVD, POR, PWM
• Number Of I /o: 13
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Slave LIN Interface Controller (SLIC) Module
14.9 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
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.
14.9.1 LIN Message Frame Header
The HEADER section of all LIN messages is transmitted by the master node in the network and contains
synchronization data, as well as the identifier to define what information is to be contained in the message
frame. Formally, the header is comprised of three parts:
The first two components are present to allow the LIN slave nodes to recognize the beginning of the
message frame and derive the bit rate of the master module.
The SYNCH BREAK allows the slave to see the beginning of a message frame on the bus. The SLIC
module can receive a standard 10-bit break character for the SYNCH BREAK, or any break symbol 10 or
more bit times in length. This encompasses the LIN requirement of 13 or more bits of length for the
SYNCH BREAK character.
The SYNCH BYTE is always a 0x55 data byte, providing five falling edges for the slave to derive the bit
rate of the master node.
The identifier byte indicates to the slave what is the nature of the data in the message frame. This data
might be supplied from either the master node or the slave node, as determined at system design time.
The slave node must read this identifier, check for parity errors, and determine whether it is to send or
receive data in the data field.
More information on the HEADER is contained in
14.9.2 LIN Data Field
The data field is comprised of standard bytes (eight data bits, no parity, one stop bit) of data, from 0–8
bytes for normal LIN frames and greater than eight bytes for extended LIN frames. The SLIC module will
150
1. SYNCH BREAK
2. SYNCH BYTE (0x55)
3. IDENTIFIER FIELD
SYNCH
BREAK
HEADER
SYNCH
0x55
13 OR MORE BITS (LIN 1.3)
BYTE
IDENT
FIELD
Figure 14-14. Typical LIN MESSAGE FRAME
FIELD
DATA
0
MC68HC908QL4 Data Sheet, Rev. 8
FIELD
DATA
1
FIELD
DATA
2
14.9.7.1 LIN Message
FIELD
DATA
DATA
3
FIELD
DATA
4
FIELD
DATA
5
Headers.
FIELD
DATA
6
Freescale Semiconductor
Figure 14-14
FIELD
DATA
7
CHECKSUM
FIELD
(shown