LPC47N227TQFP Standard Microsystems (SMSC), LPC47N227TQFP Datasheet - Page 26

• Manufacturer Part Number: LPC47N227TQFP
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47N227TQFP

• Lead Free Status / RoHS Status: Not Compliant

BIT 6 MOTOR ENABLE 2
The MTR2 disk interface output is not supported.
BIT 7 MOTOR ENABLE 3
The MTR3 disk interface output is not supported.
Tape Drive Register (TDR)
Address 3F3 READ/WRITE
The Tape Drive Register (TDR) is included for 82077 software compatibility and allows the user to assign
tape support to a particular drive during initialization. Any future references to that drive automatically
invokes tape support. The TDR Tape Select bits TDR.[1:0] determine the tape drive number. Table 5
illustrates the Tape Select Bit encoding. Note that drive 0 is the boot device and cannot be assigned tape
support.
unaffected by a software reset.
Note: The LPC47N227 supports one floppy drive directly on the FDC interface pins and two floppy drives
on the Parallel Port.
Normal Floppy Mode
Bit 5
Bit 5
X
X
1
0
1
0
The remaining Tape Drive Register bits TDR.[7:2] are tristated when read.
DIGITAL OUTPUT
DIGITAL OUTPUT
Bit 4
Bit 4
REGISTER
REGISTER
X
X
1
0
1
0
Table 4 – Internal 2 Drive Decode (Drives 0 and 1 Swapped)
TAPE SEL1
(TDR.1)
Bit1
Bit1
X
X
0
0
0
0
0
0
1
1
Table 3 – Internal 2 Drive Decode (Normal)
Bit 0
Bit 0
X
X
0
1
0
1
DRIVE SELECT OUTPUTS
DRIVE SELECT OUTPUTS
Table 5 – Tape Select Bits
DRIVE
TAPE SEL0
0
1
nDS1
nDS1
(TDR.0)
1
0
1
0
1
1
(ACTIVE LOW)
(ACTIVE LOW)
0
1
0
1
26
nDS0
nDS0
0
1
1
1
0
1
DOR VALUE
DRIVE SELECTED
1CH
2DH
None
MOTOR ON OUTPUTS
MOTOR ON OUTPUTS
nMTR1
nMTR1
nBIT 5
nBIT 5
nBIT 5
nBIT 4
nBIT 4
nBIT 4
1
2
3
(ACTIVE LOW)
(ACTIVE LOW)
nMTR0
nMTR0
nBIT 4
nBIT 4
nBIT 4
nBIT 5
nBIT 5
nBIT 5
The TDR is