M69030 Asiliant Technologies, M69030 Datasheet - Page 151

• Manufacturer Part Number: M69030
• Manufacturer: Asiliant Technologies

Specifications of M69030

• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Operating Temperature (max): 70C
• Rad Hardened: No
• Lead Free Status / Rohs Status: Supplier Unconfirmed

SR01
read/write at I/O address 3C5h with index at address 3C4h set to 01h
shadowed for pipelines A and B
7-6
5
4
3
2
1
0
`efmp
A
B

Reserved
Screen Off
Shift 4
Dot Clock Divide
Shift Load
Reserved
8/9 Dot Clocks
69030 Databook
7
Reserved
Reserved
Clocking Mode Register
0: Permits normal operation
1: Disables all graphics output except for video playback windows and turns off the picture-
generating logic allowing the full memory bandwidth to be available for both host CPU
accesses and accesses by the multimedia engine for video capture and playback functions.
Synchronization pulses to the display, however, are maintained. Setting this bit to 1 can be
used as a way to more rapidly update the frame buffer.
0: Causes the video data shift registers to be loaded every 1 or 2 character clock cycles,
depending on bit 2 of this register.
1: Causes the video data shift registers to be loaded every 4 character clock cycles.
Setting this bit to 1 divides the dot clock by two and stretches all timing periods. This bit is
used in standard VGA 40-column text modes to stretch timings to create horizontal
resolutions of either 320 or 360 pixels as opposed to 640 or 720 pixels, normally used in
standard VGA 80-column text modes.
0: Pixel clock is left unaltered.
1: Pixel clock is divided by 2.
This bit is ignored if bit 4 of this register is set to 1.
0: Causes the video data shift registers to be loaded on every character clock, if bit 4 of
this register is set to 0.
1: Causes the video data shift registers to be loaded every 2 character clocks, provided
that bit 4 of this register is set to 0.
0: Selects 9 dot clocks (9 horizontal pixels) per character in text modes with a horizontal
resolution of 720 pixels
1: Selects 8 dot clocks (8 horizontal pixels) per character in text modes with a horizontal
resolution of 640 pixels
6
Screen Off
Screen Off
5
Sequencer Registers
Shift 4
Shift 4
4
Dot Clock
Dot Clock
Divide
Divide
3
Shift Load
Shift Load
2
Reserved
Reserved
Revision 1.3 11/24/99
1
8/9 Dot
8/9 Dot
Clocks
Clocks
0
10-3