lan83c175 Standard Microsystems Corp., lan83c175 Datasheet - Page 40

• Manufacturer Part Number: lan83c175
• Description: Ethernet Cardbus Integrated Controller With Modem Support Corporation
• Manufacturer: Standard Microsystems Corp.

manually (by writing to this register) does not
effect the TXUGO bit.
7 - Transmit queue empty - set when NIC
reads a transmit descriptor that is still owned
by the host.
automatically when the TXQUEUED bit in the
command register is set.
interrupt manually (by writing to this register)
does not effect the TXQUEUED bit.
6 - TCC: Transmit chain complete - set when
the
processed.
5 - TXC: Transmit complete - set when a
packet has been successfully transmitted or
aborted and the IAF bit is set for that frame.
4 - RXE: Receive error - set when a CRC error
occurs and Monitor mode is off.
3 - OVW: Receive buffer overflow warning -
set when a frame is received and local receive
buffer space is full.
2 - RQE: Receive queue empty - set when NIC
reads a receive descriptor that is still owned
by the host.
automatically when the RXQUEUED bit in the
command register is set.
interrupt manually (by writing to this register)
does not effect the RXQUEUED bit.
1 - HCC: Header copy complete - set when
receive frame header has been copied into
host memory.
0 - RCC: Receive copy complete - set when
receive frame has been copied into host
memory.
complete
transmit
This interrupt is cleared
This interrupt is cleared
chain
Clearing this
Clearing this
has
been
40
08 - INTERRUPT MASK
Reset Value: 000000000000000
This register is used to enable certain interrupt
sources selectively.
corresponding interrupt to cause an interrupt
request.
sources.
31 through 15: Unused.
14 through 0: Interrupt enables.
0C - GENERAL CONTROL
Reset Value: 000000100000000
31 through 15: Unused.
14 - RESET PHY: This bit is or'ed with the
CardBus nRST input to generate the nPHYRST
output for the physical layer device.
13 and 12 - SOFT[1:0]: These two read/write bits
are provided for use by the
They do not affect hardware operation.
11 through 10 - MEMORY READ CONTROL:
These bits control which CardBus command the
transmit DMA will use when bursting data over the
CardBus bus. When bit 11 is set, the transmit
DMA will use the CardBus "memory read line"
command. When bit 10 is set, the transmit DMA
will use the CardBus "memory read multiple"
command. When neither bit is set the transmit
DMA will use the CardBus "memory read"
command.
"memory read line" may enhance performance
on some machines.
9 and 8 - RECEIVE FIFO THRESHOLD: Controls
the level at which the CardBus
machine begins to empty the receive FIFO.
Default
THR_SEL[0].
is 1/2 full.
Bits that are 0 block their interrupt
Use of "memory read multiple" or
Bits that are 1 allow the
D9 = THR_SEL[1], D8 =
software
burst state
driver.