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
P3.12
Pin Name
LACD
Descriptions
LCD alternating signal
Dot clock
P3.13
P3.14
P3.15
P4.0
LCLK
LP
Line signal
FP
First line marker
LD0
LD1
LD2
LD3
LCD data output D0
LCD data output D1
LCD data output D2
LCD data output D3
P4.1
P4.2
P4.3
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
SONIX [ SONIX TECHNOLOGY COMPANY ]
