B69000 Asiliant Technologies, B69000 Datasheet - Page 139

• Manufacturer Part Number: B69000
• Manufacturer: Asiliant Technologies

Specifications of B69000

• Lead Free Status / Rohs Status: Supplier Unconfirmed

10-4
SR02
read/write at I/O address 3C5h with index at address 3C4h set to 02h
Note: This register is referred to in the VGA standard as the Map Mask Register. However, the word “map”
is used with multiple meanings in the VGA standard and was, therefore, deemed too confusing, hence the
reason for calling it the Plane Mask Register.
7-4
3-0
&+,36
7
Reserved
Memory Plane 3 through Memory Plane 0
These four bits of this register control processor write access to the four memory maps:
0: Disables CPU write access to the given memory plane
1: Enables CPU write access to the given memory plane
In both the Odd/Even Mode and the Chain 4 Mode, these bits still control access to the
corresponding color plane.
69000 Databook
Plane Mask Register
6
Reserved
5
Subject to Change Without Notice
Sequencer Registers
4
Memory
Plane 3
3
Memory
Plane 2
2
Memory
Plane 1
Revision 1.3 8/31/98
1
Memory
Plane 0
0