W83877TF Datasheet, PDF (47/154 Pages) Winbond – I/O chip disk drive adapter

765 43
11 1 1
21
0
HIGH DENS
DRATE0
DRATE1
W83877TF
DSKCHG (Bit 7):
This bit indicates the complement of the DSKCHG input.
DSKCHG
Bit 6-3: These bits are always a logic 1 during a read.
DRATE1 DRATE0 (Bit 2, 1):
These two bits select the data rate of the FDC. Refer to the DR register bits 1 and 0 for the settings
corresponding to the individual data rates.
HIGH DENS (Bit 0):
0 500 KB/S or 1 MB/S data rate (high density FDD)
1 250 KB/S or 300 KB/S data rate
In the PS/2 Model 30 mode, the bit definitions are as follows:
765 43 21 0
00 0
DRATE0
DRATE1
NOPREC
DMAEN
DSKCHG (Bit 7):
This bit indicates the status of DSKCHG input.
Bit 6-4: These bits are always a logic 1 during a read.
DMAEN (Bit 3):
This bit indicates the value of DO REGISTER bit 3.
NOPREC (Bit 2):
This bit indicates the value of CC REGISTER NOPREC bit.
DRATE1 DRATE0 (Bit 1, 0):
These two bits select the data rate of the FDC.
DSKCHG
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Publication Release Date: March 1998
Version 0.61