FDC37B727-NS Standard Microsystems (SMSC), FDC37B727-NS Datasheet - Page 107

• Manufacturer Part Number: FDC37B727-NS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37B727-NS

• Pin Count: 128
• Lead Free Status / RoHS Status: Compliant

The Floppy Disk Control signals are available
optionally on the parallel port pins.
mode is selected, the parallel port is not available.
There are two modes of operation, PPFD1 and
PPFD2.
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.
2.
3.
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.
NOTE
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 FDC
POWER
CR22.3
PORT
is enabled; i.e., STROBE = AUTOFD = SLC = 0 and nINIT = 1.
These modes can be selected in the
X
1
0
LD3:CRF1.1
PARALLEL PORT FLOPPY DISK CONTROLLER
PARALLEL PORT FDC
TABLE 45 - PARALLEL PORT FDD CONTROL
0
0
1
X
CONTROL
When this
LD3:CRF1.0
X
0
0
1
107
2.
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 42.
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 41
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, nSTEP, nDS1, nDS0, nMTR0, 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
Register
read
PARALLEL PORT
(NOTE
STATE
OFF
OFF
as
ON
1
"cable
)
not