M69000 Asiliant Technologies, M69000 Datasheet - Page 294

• Manufacturer Part Number: M69000
• Manufacturer: Asiliant Technologies

Specifications of M69000

• Lead Free Status / Rohs Status: Supplier Unconfirmed

BR05
read/write at memory space offset 0x400014h
word or doubleword accessible
31-22
21-3
2-0
&+,36
31
15
Reserved (Writable)
Pattern Address
Reserved
14
30
69000 Databook
Pattern Address Register
13
29
These bits should always be written with the value of 0.
These bits specify the starting address of the pattern data within the frame buffer as an
offset from the beginning of the frame buffer to where the first byte of pattern data is located.
The pattern data is always an 8x8 array of pixels that is always stored in frame buffer
memory as a single contiguous block of bytes. The pattern data must be located on a
boundary within the frame buffer that is equivalent to its size, and its size depends on the
pattern data’s color depth. The color depth may be 1 bit per pixel if the pattern data is
monochrome or it may be 8, 16, or 24 bits per pixel if the pattern data is in color (the color
depth of a color pattern must match the color depth to which the BitBLT engine has been
set). Monochrome patterns require 8 bytes, and so the pattern data must start on a
quadword boundary. Color patterns of 8, 16, and 24 bits per pixel color depth must start
on 64-byte, 128-byte, and 256-byte boundaries, respectively.
Note: In the case of 24 bits per pixel, each row of 8 pixels of pattern data takes up 32
consecutive bytes, not 24. The pattern data is formatted so that for each row there is a
block of 8 sets of 3 bytes (each set corresponding to one of the 8 pixels), followed by a block
of the 8 extra bytes. When the BitBLT engine reads 24 bit-per-pixel pattern data, it will read
only the first 24 bytes of each row of pattern data, picking up only the 8 sets of 3 bytes for
the 8 pixels in that row, and entirely ignoring the remaining 8 bytes.
These bits always return 0 when read.
12
28
(0000:0000:00)
27
11
Reserved
Pattern Address Bits 15-3
(xxxx:xxxx:xxxx:x)
26
10
Subject to Change Without Notice
25
9
BitBLT Registers
24
8
23
7
22
6
21
5
Pattern Address Bits 21-16
20
4
19
(xx:xxxx)
3
Revision 1.3 8/31/98
18
2
Reserved
(000)
17
1
17-11
16
0