w83977atf Winbond Electronics Corp America, w83977atf Datasheet - Page 83

• Manufacturer Part Number: w83977atf
• Description: Winbond I/o
• Manufacturer: Winbond Electronics Corp America

Bit 4:
Bit 3:
Bit 2:
Bit 1:
Bit 0:
4.4.3 Reg3 - Sets Select Register (SSR)
Reading this register returns E0H. Writing a value selects Register Set.
Refault Value
Reg.
SSR
DMATHL
0
1
ALOOP - All Mode Loopback
A write to 1 will enable loopback in all modes.
D_CHSW - DMA TX/RX Channel Swap
If only one DMA channel operates in MIR/FIR mode, then the DMA channel can be
swapped.
A write to 1 will enable output data when ALOOP=1.
DMATHL - DMA Threshold Level
Set DMA threshold level as shown in the following table.
DMA_F - DMA Fairness
ADV_SL - Advanced Mode Select
A write to 1 selects advanced mode.
SSR7
Bit 7
1
DMA_F
0
1
SSR6
Bit 6
D_CHSW
1
0
1
16-Byte
13
23
SSR5
Bit 5
TX FIFO Threshold
1
DMA request (DREQ) is forced inactive after 10.5us
SSR4
DMA Channel Selected
Bit 4
- 64 -
0
Receiver (Default)
Transmitter
No effect DMA request.
Function Description
SSR3
32-Byte
Bit 3
0
13
7
Publication Release Date:April 1998
SSR2
Bit 2
0
W83977ATF
RX FIFO Threshold
PRELIMINARY
(16/32-Byte)
SRR1
Bit 1
0
10
4
Revision 0.52
SRR0
Bit 0
0