FDC37B78X SMSC Corporation, FDC37B78X Datasheet - Page 109

• Manufacturer Part Number: FDC37B78X
• Description: Enhanced Super I/O Controller with ACPI Support/ Real Time Clock and Consumer IR
• Manufacturer: SMSC Corporation

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.
selected in the Parallel Port Mode Register, as
defined in the Parallel Port Mode Register,
Logical Device 3, at 0xF1.
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.
2.
3.
The following parallel port pins are read as
follows by a read of the parallel port register:
1.
NOTE
Note: nPDACK, PDRQ and PINTR refer to the
nDACK, DRQ and IRQ chosen for the parallel
PORT POWER
nPDACK: high-Z
PDRQ: not ECP = high-Z, ECP & dmaEn =
0, ECP & not dmaEn = high-Z
PINTR: not active, this is hi-Z or Low
depending on settings.
Data Register (read) = last Data Register
(write)
PARALLEL
1
: The Parallel Port Control register reads as “Cable Not Connected” when the Parallel Port
CR22.3
FDC is enabled; i.e., STROBE = AUTOFD = SLC = 0 and nINIT = 1.
X
1
0
port.
PARALLEL PORT FLOPPY DISK CONTROLLER
LD3:CRF1.1
These modes can be
PARALLEL PORT FDC
TABLE 46 - PARALLEL PORT FDD CONTROL
X
0
0
1
PPFD1 has only
CONTROL
LD3:CRF1.0
X
0
0
1
109
1.
3.
The following FDC pins are all in the high
impedence state when the PPFDC is actually
selected by the drive select register:
1.
2.
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.
PARALLEL PORT
Control
connected" STROBE, AUTOFD and SLC =
0 and nINIT =1
Status Register reads: nBUSY = 0, PE = 0,
SLCT = 0, nACK = 1, nERR = 1
nWDATA, DENSEL, nHDSEL, nWGATE,
nDIR,
nMTR1.
If PPFDx is selected, then the parallel port
can not be used as a parallel port until
"Normal" mode is selected.
FDC STATE
OFF
OFF
ON
nSTEP,
Register
nDS1,
read
PARALLEL PORT
(NOTE
STATE
nDS0,
as
OFF
OFF
ON
"cable
1
)
nMTR0,
not