M69030 Asiliant Technologies, M69030 Datasheet - Page 133

• 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

CR30
read/write at I/O address 3B5h/3D5h with index at address 3B4h/3D4h set to 30h
shadowed for pipelines A and B
7-4
3-0
`efmp
A
B

Reserved
Vertical Total Bits 11-8
69030 Databook
7
Extended Vertical Total Register
These bits should always be written with the value of 0.
The vertical total is a 10-bit or 12-bit value that specifies the total number of scanlines. This
includes the scanlines both inside and outside of the active display area.
In standard VGA modes, where bit 0 of the I/O Control Register (XR09) is set to 0, the
vertical total is specified with a 10-bit value. The 8 least significant bits of the vertical total
are supplied by bits 7-0 of the Vertical Total Register (CR06), and the 2 most significant bits
are supplied by bits 5 and 0 of the Overflow Register (CR07). In standard VGA modes,
these bits 3-0 of this register (CR30) are not used.
In extended modes, where bit 0 of the I/O Control Register (XR09) is set to 1, the vertical
total is specified with a 12-bit value. The 8 least significant bits of this value are supplied
by bits 7-0 of the Vertical Total Register (CR06), and the 4 most significant bits are supplied
by bits 3-0 of this register (CR30).
This 10-bit or 12-bit value should be programmed to be equal to the total number of
scanlines, minus 2.
6
Reserved
Reserved
5
CRT Controller Registers
4
3
Vertical Total Bits 11-8
Vertical Total Bits 11-8
2
Revision 1.3 11/24/99
1
0
9-31