W83627HF Datasheet, PDF (162/185 Pages) Winbond – WINBOND I/O

W83627HF/F
PRELIMINARY
CRF2 (Default 0xFF)
Bit 7 - 6: FDD D Drive Type
Bit 5 - 4: FDD C Drive Type
Bit 3 - 2: FDD B Drive Type
Bit 1 - 0: FDD A Drive Type
CRF4 (Default 0x00)
FDD0 Selection:
Bit 7: Reserved.
Bit 6: Precomp. Disable.
= 1 Disable FDC Precompensation.
= 0 Enable FDC Precompensation.
Bit 5: Reserved.
Bit 4 - 3: DRTS1, DRTS0: Data Rate Table select (Refer to TABLE A).
= 00 Select Regular drives and 2.88 format
= 01 3-mode drive
= 10 2 Meg Tape
= 11 Reserved
Bit 2: Reserved.
Bit 1:0: DTYPE0, DTYPE1: Drive Type select (Refer to TABLE B).
CRF5 (Default 0x00)
FDD1 Selection: Same as FDD0 of CRF4.
TABLE A
Drive Rate Table
Select
DRTS1 DRTS0
0
0
0
1
1
0
Data Rate
DRATE1
1
0
0
1
1
0
0
1
1
0
0
1
DRATE0
1
0
1
0
1
0
1
0
1
0
1
0
Selected Data Rate
MFM
1Meg
500K
300K
250K
1Meg
500K
500K
250K
1Meg
500K
2Meg
250K
FM
---
250K
150K
125K
---
250K
250K
125K
---
250K
---
125K
SELDEN
1
1
0
0
1
1
0
0
1
1
0
0
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Publication Release Date: Jul 1999
Revision 0.53