W90221X Winbond Electronics Corp America, W90221X Datasheet - Page 85

• Manufacturer Part Number: W90221X
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

FIFO 3/4 Threshold Register (FF34T)
Port address: 0x0000014c
Bits 0-2
Bits 3-7
Bits 8-10
Bits 11-15
Bits 16-18
Bits 19-23
Bits 24-26
Bits 27-31
W90221X version 0.6
16
24
0
8
Reserved
Reserved
Reserved
Reserved
17
25
1
9
Reserved
Third FIFO high threshold
When the third frame buffer FIFO is filled up to this threshold, the
FIFO is ready to release DRAM access to other pending requests.
The initial value is 18H.
Reserved
Third FIFO low threshold
When the third frame buffer FIFO is fetched down to this threshold by
graphics controller, a request is generated to the DRAM controller for
DRAM access. The initial value is 0CH.
Reserved
Fourth FIFO high threshold
When the fourth frame buffer FIFO is filled up to this threshold, the
FIFO is ready to release DRAM access to other pending requests.
The initial value is 18H.
Reserved
Fourth FIFO low threshold
When the fourth frame buffer FIFO is fetched down to this threshold
by graphics controller, a request is generated to the DRAM controller
for DRAM access. The initial value is 0CH.
10
18
26
2
Access type: read/write
11
19
27
3
12
20
28
4
SRM3_HT
SRM4_HT
SRM3_LT
SRM4_LT
13
21
29
5
14
22
30
6
Default: 0x---
15
23
31
7
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