FDC37B78X 查看數據表（PDF） - SMSC -> Microchip

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FDC37B78X

Enhanced Super I/O Controller with ACPI Support, Real Time Clock and Consumer IR

SMSC -> Microchip 

PARALLEL PORT FLOPPY DISK CONTROLLER

The Floppy Disk Control signals are available

optionally on the parallel port pins. When this

mode is selected, the parallel port is not

available. There are two modes of operation,

PPFD1 and PPFD2. These modes can be

selected in the Parallel Port Mode Register, as

defined in the Parallel Port Mode Register,

Logical Device 3, at 0xF1. PPFD1 has only

drive 1 on the parallel port pins; PPFD2 has

drive 0 and 1 on the parallel port pins.

When the PPFDC is selected the following pins

are set as follows:

1. nPDACK: high-Z

2. PDRQ: not ECP = high-Z, ECP & dmaEn =

0, ECP & not dmaEn = high-Z

3. PINTR: not active, this is hi-Z or Low

depending on settings.

Note: nPDACK, PDRQ and PINTR refer to the

nDACK, DRQ and IRQ chosen for the parallel

port.

The following parallel port pins are read as

follows by a read of the parallel port register:

1. Data Register (read) = last Data Register

(write)

1. Control Register read as "cable not

connected" STROBE, AUTOFD and SLC =

0 and nINIT =1

3. Status Register reads: nBUSY = 0, PE = 0,

SLCT = 0, nACK = 1, nERR = 1

The following FDC pins are all in the high

impedence state when the PPFDC is actually

selected by the drive select register:

1. nWDATA, DENSEL, nHDSEL, nWGATE,

nDIR, nSTEP, nDS1, nDS0, nMTR0,

nMTR1.

2. If PPFDx is selected, then the parallel port

can not be used as a parallel port until

"Normal" mode is selected.

The FDC signals are muxed onto the Parallel

Port pins as shown in TABLE 47.

For ACPI compliance the FDD pins that are

multiplexed onto the Parallel Port function

independently of the state of the Parallel Port

controller. For example, if the FDC is enabled

onto the Parallel Port the multiplexed FDD

interface functions normally regardless of the

Parallel Port Power control, CR22.3. TABLE 46

illustrates this functionality.

TABLE 46 - PARALLEL PORT FDD CONTROL

PARALLEL

PARALLEL PORT FDC

PARALLEL PORT PARALLEL PORT

PORT POWER

CONTROL

FDC STATE

STATE

CR22.3

LD3:CRF1.1 LD3:CRF1.0

1

0

0

OFF

ON

0

0

0

OFF

OFF

X

1

X

ON

OFF

X

1

(NOTE1)

NOTE1: The Parallel Port Control register reads as “Cable Not Connected” when the Parallel Port

FDC is enabled; i.e., STROBE = AUTOFD = SLC = 0 and nINIT = 1.

109

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