AN2343 Freescale Semiconductor / Motorola, AN2343 Datasheet - Page 5

• Manufacturer Part Number: AN2343
• Description: HC908EY16 LIN Monitor
• Manufacturer: Freescale Semiconductor / Motorola

Interfacing a LCD
display with the
Sample Evaluation
Board
MOTOROLA
Once the id has been determined, LIN_GetMsg is used to retrieve the last
message data received on the bus.
This data is written onto the display, along with the appropriate message id.
A simplified block diagram of the MCU interfacing with the display would be:
As can seen from the diagram, only four lines are being used as the data bus
between the EY16 & the display. This complicates the software slightly, since
any data writes / reads take place over two cycles rather than one. However,
this makes the hardware interface much more straightforward, minimising the
lines required to drive the display.
During initial power on, the display defaults to 8 bit mode. Hence one of the
essential events in the display initialisation routine changes this default into 4
bit mode.
All display actions should be preceded by examining the busy flag, which is the
MSB of a two byte register read.
The majority of the software routines are very simple and self-explanatory:
please see the attached software listings with comments.
Freescale Semiconductor, Inc.
For More Information On This Product,
HC908EY16
Go to: www.freescale.com
HC908EY16 LIN Monitor
PTA6
PTA5
PTB2
PTB1
PTB0
PTC1
PTC0
VDD
VSS
14
13
12
11
2
4
5
6
1
VDD
RS
RW
E
D7
D6
D5
D4
VSS
Display
Software: Demonstration of LIN functionality
3
VDD
-
AN2343/D
10K
5