FDC37C935-QS Standard Microsystems (SMSC), FDC37C935-QS Datasheet - Page 95

• Manufacturer Part Number: FDC37C935-QS
• Manufacturer: Standard Microsystems (SMSC)

Specifications of FDC37C935-QS

• Lead Free Status / RoHS Status: Supplier Unconfirmed

tFIFO regardless of the value of the direction bit.
FIFO, then reading the tFIFO will return 44h,
33h, 22h in the same order as was written.
cnfgA (Configuration Register A)
ADDRESS OFFSET = 400H
Mode = 111
This register is a read only register. When read,
10H is returned. This indicates to the system
that this is an 8-bit implementation. (PWord = 1
byte)
cnfgB (Configuration Register B)
ADDRESS OFFSET = 401H
Mode = 111
BIT 7 compress
This bit is read only. During a read it is a low
level.
support hardware RLE compression.
support hardware de-compression!
BIT 6 intrValue
Returns the value on the ISA iRq line to
determine possible conflicts.
BITS [3:0] Parallel Port IRQ
Refer to Table "A" on page 169.
BITS [2:0] Parallel Port DMA
Refer to Table "B" on page 169.
ecr (Extended Control Register)
ADDRESS OFFSET = 402H
Mode = all
This register controls the extended ECP parallel
port functions.
For example if 44h, 33h, 22h is written to the
This means that this chip does not
It does
95
BITS 7,6,5
These bits are Read/Write and select the Mode.
BIT 4 nErrIntrEn
Read/Write (Valid only in ECP Mode)
1:
0:
BIT 3 dmaEn
Read/Write
1:
0:
BIT 2 serviceIntr
Read/Write
1:
0:
case dmaEn=1:
case dmaEn=0 direction=0:
case dmaEn=0 direction=1:
Disables the interrupt generated on the
asserting edge of nFault.
Enables an interrupt pulse on the high to
low edge of nFault. Note that an interrupt
will be generated if nFault is asserted
(interrupting) and this bit is written from a 1
to a 0. This prevents interrupts from being
lost in the time between the read of the ecr
and the write of the ecr.
Enables DMA (DMA starts when serviceIntr
is 0).
Disables DMA unconditionally.
Disables DMA and all of the service
interrupts.
Enables one of the following 3 cases of
interrupts. Once one of the 3 service
interrupts has occurred serviceIntr bit shall
be set to a 1 by hardware. It must be reset
to 0 to re-enable the interrupts. Writing this
bit to a 1 will not cause an interrupt.
During DMA (this bit is set to a 1 when
terminal count is reached).
This bit shall be set to 1 whenever there are
writeIntrThreshold or more bytes free in the
FIFO.
This bit shall be set to 1 whenever there are
readIntrThreshold or more valid bytes to be
read from the FIFO.