FDC37C78_07 SMSC [SMSC Corporation], FDC37C78_07 Datasheet - Page 13

• Manufacturer Part Number: FDC37C78_07
• Description: Floppy Disk Controller
• Manufacturer: SMSC [SMSC Corporation]

TAPE DRIVE REGISTER (TDR)
Address 3F3 READ/WRITE
This register is included for 82077 software
compatability. The robust digital data separator
used in the FDC37C78 does not require its
characteristics modified for tape support.
contents of this register are not used internal to the
device.
reset.
mode.
Bit 7
Bit 7
X
X
X
X
X
X
1
0
1
0
Bits 2-7 are tri-stated when read in this
Bit 6
Bit 6
DIGITAL OUTPUT REGISTER
The TDR is unaffected by a software
DIGITAL OUTPUT REGISTER
X
X
X
X
X
X
1
0
1
0
Bit 5
Bit 5
X
X
X
X
X
X
1
0
1
0
Table 6 - Internal 4 Drive Decode - Drives 0 and 1 Swapped
Bit 4
Bit 4
X
X
X
1
0
1
X
X
X
0
Table 5 - Internal 4 Drive Decode - Normal
Bit1
Bit1
X
0
0
1
1
0
0
1
1
X
Bit 0
Bit 0
0
1
0
1
X
X
0
1
0
1
nDS3
nDS3
The
1
1
1
0
1
DRIVE SELECT OUTPUTS
1
1
1
0
1
DRIVE SELECT OUTPUTS
(ACTIVE LOW)
nDS2
13
(ACTIVE LOW)
nDS2
1
1
0
1
1
1
1
0
1
1
TAPE SEL1
nDS1
nDS1
0
1
1
1
1
1
0
1
1
1
0
0
1
1
Table 4- Tape Select Bits
nDS0
nDS0
1
0
1
1
1
0
1
1
1
1
nMTR3
nBIT 7
nBIT 7
nBIT 7
nBIT 7
nBIT 7
nMTR3
TAPE SEL2
nBIT 7
nBIT 7
nBIT 7
nBIT 7
nBIT 7
MOTOR ON OUTPUTS
0
1
0
1
MOTOR ON OUTPUTS
nMTR2
nBIT 6
nBIT 6
nBIT 6
nBIT 6
nBIT 6
nMTR2
nBIT 6
nBIT 6
nBIT 6
nBIT 6
nBIT 6
(ACTIVE LOW)
(ACTIVE LOW)
SELECTED
nMTR1
nMTR1
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 5
nBIT 5
nBIT 5
nBIT 5
nBIT 5
DRIVE
None
1
2
3
nMTR0
nMTR0
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 4
nBIT 5
nBIT 5
nBIT 5
nBIT 5
nBIT 5