W83977G Winbond Electronics Corp America, W83977G Datasheet - Page 39

• Manufacturer Part Number: W83977G
• Description: W83877TF plus KBC, CIR, RTC, Pb-free
• Manufacturer: Winbond Electronics Corp America

This bit indicates the status of DSB output pin.
This bit indicates the status of DSA output pin.
WD F/F(Bit 4):
This bit indicates the complement of the latched WD output pin at every rising edge of the WD output
pin.
RDATA F/F(Bit 3):
This bit indicates the complement of the latched RDATA output pin .
WE F/F (Bit 2):
This bit indicates the complement of latched WE output pin.
0
1
0
1
5.2.3
The Digital Output Register is a write-only register controlling drive motors, drive selection, DRQ/IRQ
enable, and FDC resetting. All the bits in this register are cleared by the MR pin. The bit definitions are
as follows:
5.2.4
This register is used to assign a particular drive number to the tape drive support mode of the data
separator. This register also holds the media ID, drive type, and floppy boot drive information of the
floppy disk drive. In normal floppy mode, this register includes only bit 0 and 1. The bit definitions are
as follows:
DSA (Bit 5):
DSD (Bit 1):
DSC (Bit 0):
W83977F-A/ W83977G-A/ W83977AF-A/ W83977AG-A
Drive D has been selected
Drive D has not been selected
Drive C has been selected
Drive C has not been selected
Digital Output Register (DO Register) (Write base address + 2)
Tape Drive Register (TD Register) (Read base address + 3)
7
6
5
4
3
2
1-0
-31 -
Drive Select: 00 select drive A
Floppy Disk Controller Reset
Active low resets FDC
DMA and INT Enable
Active high enable DRQ/IRQ
Motor Enable A. Motor A on when active high
Motor Enable B. Motor B on when active high
Motor Enable C. Motor C on when active high
Motor Enable D. Motor D on when active high
01 select drive B
10 select drive C
11 select drive D
Publication Release Date: May 2006
Revision 0.60