SPC8106 S-MOS Systems, SPC8106 Datasheet - Page 137

• Manufacturer Part Number: SPC8106
• Description: LCD/CRT VGA CONTROLLER
• Manufacturer: S-MOS Systems

bit 7
bit 6
bit 5
bit 3
bit 2
bit 1
bit 0
bit 5
bit 4
SPC8106
05 Extended Function Register 1 RW
Packed 4-bit/
pixel Mode
Enable
06 Extended Function Register 1B RW
n/a
411-1.0
Hardware
Zoom
Enable
n/a
S-MOS Systems, Inc. • Tel: [phone] • Fax: [phone] • http://www.smos.com
Packed 4-bit per Pixel Mode Enable
When this bit = 1 the 4-bit per pixel packed pixel format video mode is enabled.
Hardware Zoom Enable
When this bit = 1 every second display pixel and line are removed to that the image is shrunk in
half. This applies to all video modes. This bit is intended to be used with sub-VGA single drive sin-
gle panels, thus allowing a 640 x 480 image to be displayed on a 320 x 240 panel.
Sprite/HW Cursor Enable This bit is used to enable the sprite and hardware cursor functions. When
this bit = 0, the sprite/hardware cursor function is disabled. When this bit = 1, the sprite/hardware
cursor is enabled. See “Sprite/HW Cursor Registers” on page 113 for more information.
Start Address Bit SA16
This bit is used to set the most significant display start address bit when utilizing the upper 256K
bytes of display memory to provide the Extended Display Page function (see below). Along with the
lower 16 bits of start address in CRTC registers 0C and 0D, this bit allows setting the start address
of the image displayed to be anywhere in the 512K address space. For this bit to have an effect, the
Extended Display Page Enable bit must be set to 1.
Extended Display Page Enable
This bit is used to enable the Extended Display Page function. This function allows the display
memory to wrap into the upper 256K bytes, and for 256K bytes of memory to be displayed starting
anywhere in the entire 512K byte extended display memory space. If this bit is set to 1, then the
extended display page function is enabled. If this bit is set to 0, then the extended display page
function is disabled.
Hi-Res 256-color Mode Enable
When this bit = 1 the 640 x 480 256-color mode for single panel LCD displays and CRT monitors is
enabled.
CPU Upper 256K Access Enable
This bit is used to enable CPU accesses into the upper 256K bytes of display memory. When this
bit = 1, the CPU can access the upper half of display memory through memory addresses B0000 -
BFFFF. The lower 256K of video memory can still be accessed at addresses A0000 - AFFFF. When
this bit = 0, only the lower 256K bytes of display memory can be accessed by the CPU. Note that
the Upper Page Swap Enable bit can be used to swap the upper/lower page addresses. This func-
tion will only be useful in planar graphics modes.
Panel Data Setup/Hold Select
When this bit = 1, 16-bit color panel data setup/hold timings are set to 1Ts/1.5Ts minimum.
When this bit = 0, 16-bit color panel data setup/hold timings are set to 1.5Ts/1Ts minimum.
RS2/D477 Control
When this bit = 1, RS2 and D477 remain active all the time.
When this bit = 0, RS2 and D477 are tri-stated in non-CRT mode and forced low and high respec-
tively in power save modes.
Sprite/HW
Cursor
Enable
Panel Data
Setup/Hold
Select
n/a
(reserved)
RS2/D477
Control
X12-SP-001-07
Start
Address Bit
SA16
Page Select
Register
Port Enable
Extended
Display Page
Enable
Horizontal
Non-display
Period Width
Hardware Functional Specification
Hi-Res 256
Color Mode
Enable
Sequencer
CPU Cycles
Disable
CPU Upper
256K
Access
Enable
LCD Power
Disable
SP1-95