w83977atg Winbond Electronics Corp America, w83977atg Datasheet - Page 146

• Manufacturer Part Number: w83977atg
• Description: W83877tf Plus Kbc, Gp I/o, Wake-up, Fir, Cir, Pb-free
• Manufacturer: Winbond Electronics Corp America

CRF2 (Default 0xFF)
When FDD is in enhanced 3-mode (CRF0.bit0=1),these bits determine SELDEN value in TABLE A of
CRF4 and CRF5 as follows.
Note: X means don't care.
CRF4 (Default 0x00)
FDD0 Selection:
Bit 1
Bit 0
Bit 7 - 6
Bit 5 - 4
Bit 3 - 2
Bit 1,0
Bit 7
Bit 6
Bit 5
Bit 4 - 3
DTYPE1
0
0
0
0
0
1
1
: DISFDDWR
= 0
= 1
: SWWP
= 0
= 1
: FDD D Drive Type
: FDD C Drive Type
: FDD B Drive Type
: FDD A Drive Type
: Reserved.
: Precomp. Disable.
= 1
= 0
: Reserved.
: DRTS1, DRTS0: Data Rate Table select (Refer to TABLE A).
= 00
= 01
= 10
= 11
Enable FDD write.
Disable FDD write (forces pins WE, WD stay high).
Normal, use WP to determine whether the FDD is write protected or not.
FDD is always write-protected.
Disable FDC Precompensation.
Enable FDC Precompensation.
Select Regular drives and 2.88 format
2 Meg Tape
Reserved
Specifical application
DPYTE0
0
0
0
0
1
0
1
DRATE1
- 138 -
X
X
1
0
0
1
0
W83977ATF/W83977ATG
DRATE0
X
X
1
0
1
0
1
SELDEN
1
1
0
0
0
1
0