W83759A Datasheet, PDF (13/41 Pages) Winbond – ADVANCED VL-IDE DISK CONTROLLER

W83759A
Continued
when ADV_P
=1
IDEN1
0
1
0
1
IDEN0
0
0
1
1
Primary IDE
disabled
disabled
enabled
enabled
Secondary IDE
disabled
enabled
disabled
enabled
CRX81h (POSP1)
Read / Write
Power-on Setting Programming 1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
ADV_P SP1_P MD1_P MD0_P PRDYEN_P SRDYEN_P IDEN1_P IDEN0_P
After power-on, the content of the POSP1 register is equal to that of the POSS1 register. The host
can program POSP1 to modify the power-on settings.
Bit 7
ADV_P
Programming application mode
0
No advanced mode application
1
Advanced mode application
Bit 6
SP1_P
Select VESA bus operating CLK
0
VLCLK 33 MHz
1
VLCLK > 33 MHz
Bit 5, 4
MD1_P,
MD0_P
Select default HDD host transfer mode
MD1_P MD0_P
0
0 Mode 0 (cycle time = 600 nS)
0
1 Mode 0+ (cycle time = 500 nS)
1
0 Mode 1 (cycle time = 400 nS)
1
1 Mode 2 (cycle time = 240 nS)
Bit 3
PRDYEN_P
Primary channel IOCHRDY flow control
0
Disable IOCHRDY flow control
1
Enable IOCHRDY flow control
Bit 2
SRDYEN_P
Secondary channel IOCHRDY flow control
0
Disable IOCHRDY flow control
1
Enable IOCHRDY flow control
Bit 1, 0
IDEN1_P,
IDEN0_P
IDE ENable control
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Publication Release Date: May 1995
Revision A1