Laptop User Manual
S3C2440A RISC MICROPROCESSOR     LCD CONTROLLER 
  15-29 
LCD Control 3 Register 
Register Address R/W  Description  Reset Value
LCDCON3  0X4D000008  R/W  LCD control 3 register  0x00000000
LCDCON3 Bit  Description  Initial state 
HBPD (TFT)  [25:19] 
TFT: Horizontal back porch is the number of VCLK periods between 
the falling edge of HSYNC and the start of active data. 
0000000 
WDLY (STN)   
STN: WDLY[1:0] bits determine the delay between VLINE and VCLK 
by counting the number of the HCLK. WDLY[7:2] are reserved. 
00 = 16 HCLK, 01 = 32 HCLK, 10 = 48 HCLK, 11 = 64 HCLK 
HOZVAL [18:8] 
TFT/STN: These bits determine the horizontal size of LCD panel. 
HOZVAL has to be determined to meet the condition that total bytes 
of 1 line are 4n bytes. If the x size of LCD is 120 dot in mono mode, 
x=120 cannot be supported because 1 line consists of 15 bytes. 
Instead, x=128 in mono mode can be supported because 1 line is 
composed of 16 bytes (2n). LCD panel driver will discard the 
additional 8 dot. 
00000000000
HFPD (TFT)  [7:0] 
TFT: Horizontal front porch is the number of VCLK periods between 
the end of active data and the rising edge of HSYNC. 
0X00 
LINEBLANK 
(STN) 
STN: These bits indicate the blank time in one horizontal line 
duration time. These bits adjust the rate of the VLINE finely. 
The unit of LINEBLANK is HCLK x 8. 
Ex) If the value of LINEBLANK is 10, the blank time is inserted to 
VCLK during 80 HCLK. 
Programming NOTE 
: In case of STN LCD, (LINEBLANK + WLH + WDLY) value should be bigger than (14+12Tmax). 
(LINEBLANK + WLH + WDLY) 
≥ (14 + 8xTmax1 + 4xTmax2 = 14 + 12Tmax) 
 LEGEND: 
   (1) 14: SDRAM Auto refresh bus acquisition cycles 
   (2) 8x Tmax1 : Cache fill cycle X the Slowest Memory access time(Ex, ROM) 
 (3) 4x Tmax2 : 0xC~0xE address Frame memory Access time 










