SA8807A

6/14

sames

PIN DESCRIPTION (Continued)

Pin

Pin

PLCC-44 DIP-40

14

2

VS[20]

LCD segment driver outputs

15

3

VS[21]

16

4

VS[22]

17

5

VS[23]

30

17

VR[0]

LCD row driver outputs

31

18

VR[1]

32

19

VR[2]

33

20

VR[3]

29

16

NC

Not connected

12

NC

24

NC

34

NC

44

NC

Designation Description

FUNCTIONAL DESCRIPTION

The SA8807A is a CMOS Liquid Crystal Driver integrated circuit for displays having 3 or

4 track multiplexed backplanes and up to 96 LCD segments.

Data exchange is performed through a Serial Peripheral Interface (SPI).

1.

Serial Peripheral (SPI) Interface

The SPI Interface is a 4 wire interface.

The device transmits the data to the Master via MISO (Master In, Slave Out).

Data from the Master is received through MOSI (Master Out, Slave In). The data

is always synchronised to the Serial Clock (SCK), which is supplied from the Master.

CE is a active high signal, the rising edge defining the start of a transfer procedure.

The transfer procedure is terminated with the falling edge of CE.

Diagram 1 illustrates the relationships between Clock, Data and Chip Enable

signals.

The SA8807A determines the clock polarity during the low to high transition of the

CE signal.