FDC37C665GT Standard Microsystems (SMSC), FDC37C665GT Datasheet - Page 31

• Manufacturer Part Number: FDC37C665GT
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37C665GT

• Lead Free Status / RoHS Status: Not Compliant

Normal Floppy Mode
Normal mode. Register 3F3 contains only bits 0 and 1. When this register is read, bits 2 - 7 are a
high impedance.
Enhanced Floppy Mode 2 (OS2)
Register 3F3 for Enhanced Floppy Mode 2 operation.
For this mode, DRATE0 and DRATE1 pins are
inputs, and these inputs are gated into bits 6
and 7 of the 3F3 register. These two bits are
not affected by a hard or soft reset.
BIT 7 MEDIA ID 1 READ ONLY (Pin 18) (See
Table 9)
BIT 6 MEDIA ID 0 READ ONLY (Pin 19) (See
Table 10)
BITS 5 and 4 Drive Type ID - These Bits reflect
two of the bits of configuration register 6.
REG 3F3
REG 3F3
DRATE1
Pin 18
Input
0
1
Tri-state
Media
Table 9 - Media ID1
DB7
DB7
ID1
CR7-DB3 = 0 CR7-DB3 = 1
Tri-state
0
1
Media
DB6
DB6
ID0
MEDIA ID1
BIT 7
Tri-state
DB5
DB5
Drive Type ID
1
0
Tri-state
DB4
DB4
31
Which two bits depends on the last drive
selected in the Digital Output Register (3F2).
(See Table 11)
BITS 3 and 2 Floppy Boot Drive - These bits
reflect the value of configuration register 7 bits
1, 0. Bit 3 = CR7 Bit DB1. Bit 2 = CR7 Bit DB0.
Bits
(READ/WRITE).
Enhanced Floppy Mode. 1.
DRATE0
Pin 19
Tri-state
Input
Floppy Boot Drive
DB3
DB3
1
0
1
and
Table 10 - Media ID0
Tri-state
CR7-DB2 = 0 CR7-DB2 = 1
DB2
DB2
0
Same as in Normal and
-
0
1
MEDIA ID0
Tape
tape sel1 tape sel0
tape sel1 tape sel0
BIT 6
DB1
DB1
Drive
1
0
DB0
DB0
Select