FDC37M817-MS Ver la hoja de datos (PDF) - SMSC -> Microchip

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FDC37M817-MS

PC98/99 Compliant Enhanced Super I/O Controller with Keyboard/Mouse Wake-Up

SMSC -> Microchip 

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 4 illustrates the Tape

Select Bit encoding. Note that drive 0 is the boot

device and cannot be assigned tape support. The

remaining Tape Drive Register bits TDR.[7:2] are

tristated when read. The TDR is unaffected by a

software reset.

Table 4 - Tape Select Bits

TAPE SEL1

TAPE SEL0

DRIVE

(TDR.1)

(TDR.0)

SELECTED

0

0

None

0

1

1

1

0

2

1

1

3

Table 5 - Internal 2 Drive Decode - Normal

DIGITAL OUTPUT

REGISTER

DRIVE SELECT OUTPUTS MOTOR ON OUTPUTS

(ACTIVE LOW)

(ACTIVE LOW)

Bit 5 Bit 4 Bit1 Bit 0

nDS1

nDS0

nMTR1

nMTR0

X

1

0

0

1

0

nBIT 5

nBIT 4

1

X

0

1

0

1

nBIT 5

nBIT 4

0

0

X

X

1

1

nBIT 5

nBIT 4

Table 6 - Internal 2 Drive Decode - Drives 0 and 1 Swapped

DIGITAL OUTPUT

REGISTER

DRIVE SELECT OUTPUTS MOTOR ON OUTPUTS

(ACTIVE LOW)

(ACTIVE LOW)

Bit 5 Bit 4 Bit1 Bit 0

nDS1

nDS0

nMTR1

nMTR0

X

1

0

0

0

1

nBIT 4

nBIT 5

1

X

0

1

1

0

nBIT 4

nBIT 5

0

0

X

X

1

1

nBIT 4

nBIT 5

21

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