B69000 Asiliant Technologies, B69000 Datasheet - Page 166

• Manufacturer Part Number: B69000
• Manufacturer: Asiliant Technologies

Specifications of B69000

• Lead Free Status / Rohs Status: Supplier Unconfirmed

PALDATA
read/write at I/O address 3C9h
7-0
&+,36
7
Palette Data Register
69000 Databook
This byte-wide data port provides read or write access to the three bytes of data carried by
palette location selected using the Palette Read Index Register (PALRX) or the Palette
Write Index Register (PALWX).
The three bytes in each palette location are written to or read from by making three
successive read or write operations. The first byte read or written always specifies the
intensity of the red component of the color specified in the selected palette location. The
second byte is always for the green component and the third byte is always for the blue
component.
When writing data to a palette location, all three bytes must be written before the hardware
will actually update the three bytes in that palette location.
When reading or writing to a palette location, it is important to ensure that neither the
Palette Read Index Register (PALRX) or the Palette Write Index Register (PALWX) are
written to before all three bytes are read or written. The logic that automatically cycles
through providing access to the bytes for the red, green and blue color components is reset
to start again with the red component after writing to either PALRX or PALWX.
6
Palette Data Register
5
Subject to Change Without Notice
Palette Registers
4
Palette Data
3
2
Revision 1.3 8/31/98
1
0
13-5