SNL320

16-Bit LCD Controller

14.2 LCD Driver Interface (1/4 bits interface)

SNL320 supports not just 8-bit interface but also 1-bit/4-bit interface for LCD driver.

For this kind LCD driver doesn’t include display RAM. All the display data is stored in

host CPU. So SNL320 has to specify a dedicate interface to drive LCD driver. Besides,

SNL320 reserves 4K words LCD Buffer (0xB000~0xBFFF) for LCD display. Hardware

circuit will send accurate signal to LCD driver automatically once the 1-bit/4-bit LCD

driver interface is enabled. The internal 4K words SRAM can support maximum

240x120 dots LCD display with 4-grey level effect.

Note : only support 4MHZ LCD clock source

14.3 Control Signals

P3.12~P3.15 & P4.0~P4.3 can be configured to be 1-bit/4-bit interface for LCD driver

just by property setting control register. Table-2 shows the relation between

P3.12~P3.15, P4.0~P4.3 and LCD driver interface.

I/O Pin

Pin Name

Descriptions

P3.12

LACD

LCD alternating signal

P3.13

LCLK

Dot clock

P3.14

LP

Line signal

P3.15

FP

First line marker

P4.0

LD0

LCD data output D0

P4.1

LD1

LCD data output D1

P4.2

LD2

LCD data output D2

P4.3

LD3

LCD data output D3

Table-2

14.4 LCD RAM Mapping

The RAM region from 0xB000 to 0xBFFF totally 4K*16 is reserved for LCD display

buffer, user just need to copy the LCD display pattern data into this area then chip will

display the pattern on LCD panel automatically.

There is a special register LBUF to specify the LCD display buffer start address.

Calculating formula of start address

49152-(SEG numbe/16)*COM number => for B/W

49152-(SEG numbe/16)*COM number*2 => for 4 gray levels

NOTE:

SEG number must be the multiple by 8.

Ver: 1.2

21

July 22, 2005