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FDC37C666GT View Datasheet(PDF) - SMSC -> Microchip

Part Name
Description
MFG CO.
'FDC37C666GT' PDF : 152 Pages View PDF
PARALLEL PORT FLOPPY DISK CONTROLLER
In this mode, the Floppy Disk Control signals
are available 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 Configuration Register 4. PPFD1
has only drive 1 on the parallel port pins; PPFD2
has drive 0 and 1 on the parallel port pins.
4. nMTR3/PDRQ (pin 99): not ECP = high-Z,
ECP & dmaEn = 0, ECP & not dmaEn =
high-Z
5. PINTR: not active, this is hi-Z or Low
depending on settings.
The following parallel port pins are read as
follows by a read of the parallel port register:
PPFD1:
Drive 0 is on the FDC pins
Drive 1 is on the Parallel port pins
Drive 2 is on the FDC pins*
Drive 3 is on the FDC pins*
PPFD2:
Drive 0 is on the Parallel port
pins
Drive 1 is on the Parallel port pins
Drive 2 is on the FDC pins*
Drive 3 is on the FDC pins*
* If ECP is selected, then direct support for
drives 2 and 3 is not available. Drives 2 and 3
are available using external decoders.
When the PPFDC is selected the following pins
are set as follows:
1. nDS2/PDIR (pin 98): not ECP = high-Z,
ECP = high
2. A10/nDS3 (pin 97): high-Z, A10 = to
internal logic.
3. nMTR2/nPDACK (pin 96): high-Z
1. Data Register (read) = last Data Register
(write)
2. Control Register are 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, nMTRO,
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 33:
76
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