W83977ATF Datasheet, PDF (34/207 Pages) Winbond – WINBOND I/O

HEAD (Bit 3):
This bit indicates the value of HEAD output.
0 side 1
1 side 0
INDEX (Bit 2):
This bit indicates the complement of INDEX output.
WP (Bit 1):
0 disk is not write-protected
1 disk is write-protected
DIR (Bit 0)
This bit indicates the direction of head movement.
0 inward direction
1 outward direction
W83977ATF
PRELIMINARY
2.2.2 Status Register B (SB Register) (Read base address + 1)
This register is used to monitor several disk interface pins in PS/2 and Model 30 modes. In PS/2
mode, the bit definitions for this register are as follows:
7 65 4 3 ²¹ 0
11
MOT EN A
MOT EN B
WE
RDATA Toggle
WDATA Toggle
Drive SEL0
Drive SEL0 (Bit 5):
This bit indicates the status of DO REGISTER bit 0 (drive select bit 0).
WDATA Toggle (Bit 4):
This bit changes state at every rising edge of the WD output pin.
RDATA Toggle (Bit 3):
This bit changes state at every rising edge of the RDATA output pin.
WE (Bit 2):
This bit indicates the complement of the WE output pin.
Publication Release Date: April 1998
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Revision 0.52