SPC8104 S-MOS Systems, SPC8104 Datasheet - Page 149

• Manufacturer Part Number: SPC8104
• Description: VGA LCD CONTROLLER
• Manufacturer: S-MOS Systems

Appendix D INITIALIZATION
Init code for SPC8104F0A 640x480 dual mono panel. This code assumes 24MHz input clock and
no power down clock. This code also assumes a possibility of an additional video card (CGA/
MDA) to be present.
SPC8104
(640x480 Single Color 8-Bit Display)
1.
2. Enable the SPC8104 chip:
3. Set the default SPC8104 CRTC address to 3Dxh to prevent any conflict with a possible monochrome card:
4. Enable the AUX registers
5. Program the AUX registers to the required default values.
6. Set video memory to A000h to prevent conflicts with MDA/CGA cards by programming the graphics control-
7. Do CGA/MDA detection. If no card is found, the SPC8104 can switch into 16 bit memory and I/O mode.
412-1.0
mov
mov
int
3c3h = 1
3C2h = 67h
AUX[DEh] = 1Ah
AUX[00h] = 00000000b
AUX[01h] = 00000011b
AUX[02h] = 00000000b
AUX[03h] = 00001000b
AUX[04h] = 00000000b
AUX[05h] = 00000000b
AUX[06h] = 00100000b
AUX[07H] = 10000000b
AUX[08h] = 00000000b
AUX[09h] = 00100101b
AUX[0Ah] = 01111101b
AUX[0Dh] = 00000000b
Graphics Controller[06h] = 04h
AUX[00h] = 11000000b
ler.
If a CGA card is found, we have to change the CRTC addressing to 3Bxh
Turn off the active video system:
ax,1201h
bl,32h
10h
S-MOS Systems, Inc. • Tel: [phone] • Fax: [phone] • http://www.smos.com
; read AUX[DEh] data (read port 3DFh).
; 8bit I/O, 8 bit memory
; autocenter+slow blink
; LCD interface register
; Doze mode 2 Clock divide
; clear clock register
; disable memory paging etc.
; LCD WF register = 20h
; frame buffer start at 256k
; bit 0 = Start Addr. B16 (R/W)
; fr.buffer end high byte
; fr.buffer end low byte
; clear scratch register
X15-SP-002-03
BIOS Functional Specification
SP2-43