FDC37M81 SMSC [SMSC Corporation], FDC37M81 Datasheet - Page 97

• Manufacturer Part Number: FDC37M81
• Description: PC98/99 Compliant Enhanced Super I/O Controller with Keyboard/Mouse Wake-Up
• Manufacturer: SMSC [SMSC Corporation]

BITS [5:3] Parallel Port IRQ (read-only)
Refer to Table 39B.
BITS [2:0] Parallel Port DMA (read-only)
Refer to Table 39C.
ecr (Extended Control Register)
ADDRESS OFFSET = 402H
Mode = all
This register controls the extended ECP parallel
port functions.
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:
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.
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BIT 2 serviceIntr
Read/Write
1:
0:
case dmaEn=1:
case dmaEn=0 direction=0:
case dmaEn=0 direction=1:
BIT 1 full
Read only
1:
0:
BIT 0 empty
Read only
1:
0:
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.
The FIFO cannot accept another byte or the
FIFO is completely full.
The FIFO has at least 1 free byte.
The FIFO is completely empty.
The FIFO contains at least 1 byte of data.