SNL310

16-Bit LCD Controller

10.2 1-Bit Interface

SNL310 supports not just 8-bit interface but also 1-bit interface LCD driver. For this

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

So host CPU has to specify a dedicate interface to drive LCD driver. Beside the

interface, SNL310 reserves the last 2K words RAM (0x0800~0x0FFF) for stored the

display data, then interface circuit will send accurate signal to LCD driver

automatically.

P3.6~P3.10 can be configured to be 1-bit interface for LCD driver just by property

setting control register. Table-3 shows the relation between P3.6~P3.10 and LCD

driver interface.

I/O Pin

Extension Bus

Descriptions

P3.6

LSD

LCD serial data output

P3.7

LCO1

LCD serial mode clock out1

P3.8

LCO2

LCD serial mode clock out2

P3.9

LFC

LCD frame inversion control

P3.10

COMS

COM data synchronize signal

Table-3

10.3 LCD RAM Assignment

Generally, those 1-bit interface LCD drivers don’t built-in the LCD display RAM. All the

display data have been stored in CPU side. The SNL310 already built-in totally 4K

words RAM, so user can set a property value of LCD RAM start address (LRSA)

register to assign a RAM location for LCD display data. The start address setting

formula is shown as bellow:

Calculating formula of start address

If SEG number divided by 16

4096-(SEG numbe/16)*COM number => for B/W

4096-(SEG numbe/16)*COM number*2 => for 4 gray levels

If SEG number can’t divided by 16

4096-((SEG numbe/16)+1)*COM number => for B/W

4096-((SEG numbe/16)+1)*COM number*2 => for 4 gray levels

Once upon user set the start address of LCD display RAM and active this interface

function, chip will send the display data out to external LCD driver at the right time.

Ver: 1.7

May 2, 2003

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