B69000 Asiliant Technologies, B69000 Datasheet - Page 195

• Manufacturer Part Number: B69000
• Manufacturer: Asiliant Technologies

Specifications of B69000

• Lead Free Status / Rohs Status: Supplier Unconfirmed

14-28
XRA1
read/write at I/O address 3D7h with index at I/O address 3D6h set to A1h
7-0
XRA2
read/write at I/O address 3D7h with index at I/O address 3D6h set to A2h
7-4
3-0
&+,36
7
7
Cursor 1 Vertical Extension
When the vertical extension feature for cursor 1 is enabled by setting bit 3 of the Cursor 1 Control
Register (XRA0) to 1, these 8 bits of this register are used to specify the height of cursor 1 in scan
lines. The number of scan lines must be a multiple of four.
This register should be programmed with a value derived from the following equation:
Cursor 1 Base Address Bits 15-12
These four bits provide part of a 22-bit value that specifies the offset from the beginning of the frame
buffer memory space where the 4KB cursor data space for cursor 1 is to be located. The six most-
significant bits of this 22-bit value are supplied by the Cursor 1 Base Address High Register (XRA3).
Cursor 1 Pattern Select
These four bits allow 1 of up to as many as 16 possible patterns contained in the cursor data space
for cursor 1 to be selected to be displayed.
The actual number of patterns depends on the size of each pattern, since the cursor data space is
limited to a total of 4KB in size. The size of each pattern depends, at least in part, on the choice of
cursor mode. See appendix D for more details concerning the cursor modes.
69000 Databook
Cursor 1 Base Address Bits 15-12
Cursor 1 Vertical Extension Register
Cursor 1 Base Address Low Register
value = ((number of scanlines)
6
6
(0000)
5
5
Subject to Change Without Notice
Cursor 1 Vertical Extension
Extension Registers
4
4
(4) - 1
(00h)
3
3
Cursor 1 Pattern Select
2
2
(0000)
Revision 1.3 8/31/98
1
1
0
0