is42g32256 ETC-unknow, is42g32256 Datasheet - Page 22

• Manufacturer Part Number: is42g32256
• Description: 256k 16-mbit Synchronous Graphics
• Manufacturer: ETC-unknow

IS42G32256
Table 13. Mask Function Procedure
22
1. Normal Write
2. Block Write
I/O masking: By Mask at Write Per Bit Mode, the selected bit planes keep the original data.
If bit plane 0, 3, 7, 9, 19, 22, 24, and 31 keep the original value.
a. STEP
b. Illustration
Pixel masking: By Pixel Data issued through DQ pin, the selected pixels keep the original data.
If Pixel 0, 4, 9, 13, 18, 22, 27, and 31 keep the original white color.
Assume 8bpp
White = “0000, 0000”, Red = “1010, 0011”, Green = “1110, 0001”, Yellow = “0000, 1111”, Blue = “1100, 0011”
a. STEP
External Data-in
Mask Register
Before Write
I. SMRS(LMR): Load mask [31-0]=“0111, 1110, 1011, 0111, 1111, 1101, 0111, 0110”
II. Row Active with DSF “H”: Write Per Bit Mode Enable
III. Perform Normal Write
I. SMRS(LCR): Load color (for 8bpp, through x32 DQ color0-3 are loaded into color registers). Load
II. Row Active with DSF “L”: I/O Mask by Write Per Bit Mode Disable
III. Block write with DQ[31-0] = “0111, 0111, 1011, 1011, 1101, 1101, 1110, 1110”
After Write
I/O (=DQ)
DQMi
(color3, color2, color1, color0) = (Blue, Green, Yellow, Red)
“1100,0011,1110,0001,0000,1111,1010,0011”
See Pixel To DQ Mapping Table.
11111111
01111110
00000000
01111110
31
DQM3=0
24
11111111
10110111
00000000
10110111
23
DQM2=0
16
00000000
11111101
11111111
00000010
15
DQM1=0
Integrated Silicon Solution, Inc.
8
ADVANCE INFORMATION SR037-0C
DQM byte masking
00000000
01110110
11111111
11111111
7
DQM0=1
0
ISSI
09/10/98
®