DM9102A
Single Chip Fast Ethernet NIC controller
1 0 0 Close descriptor by clearing owner bit of descriptor
1 0 1 Close descriptor by writing status
1 1 0 Receive process suspended due to buffer unavailable
1 1 1 Purge the current frame from the receive FIFO
because of unavailable receive buffer
16
NIS
0,RW
Normal Interrupt Summary
Normal interrupt includes any of the three conditions :
CR5<0> – TXCI : Transmit Complete Interrupt
CR5<2> – TXDU : Transmit Buffer Unavailable
CR5<6> – RXCI : Receive Complete Interrupt
15
AIS
0,RW
Abnormal Interrupt Summary
Abnormal interrupt includes any interrupt condition as shown below excluding Normal
Interrupt conditions. They are TXPS(bit1), TXJT(bit3), TXFU(bit5), RXDU(bit7),
RXPS(bit8), RXWT(bit9), TXER(bit10), GPT(bit11), SBE(bit13).
14
ERI
0,RW
Early Receive Interrupt
This bit will be set when early receive interrupt has happened.
13
SBE
0,RW
System Bus Error
The PCI system bus errors will set this bit. The type of system bus error is shown in
CR5<25:23>.
12
LCI
0,RW
Link Status Change Interrupt
This bit will be set when link status change.
11
GPT
0,RW
General-purpose Timer Expired
This bit is set to indicate the general-purpose timer (described in CR11) has expired.
10
TXER
0,RW
Transmit Early Interrupt
Transmit Early Interrupt is set when the full packet data has been moved from host
memory into transmit FIFO. It will inform the host to process next step before the
transmission end. Transmit complete event CR5<0> will clear this bit automatically.
9
RXWT
0,RW
Receive Watchdog Timer Expired
This bit is set to indicate receive watchdog timer has expired.
8
RXPS
0,RW
Receive Process Stopped
This bit is set to indicate receive process enters the stopped state.
7
RXDU
0,RW
Receive Buffer Unavailable
This bit is set when the DM9102A fetches the next receive descriptor that is still
owned by the host. Receive process will be suspended until a new frame enters or
the receive polling command is set.
6
RXCI
0,RW
Receive Complete Interrupt
This bit is set when a received frame is fully moved into host memory and receive
status has been written to descriptor. Receive process is still running and continues to
fetch next descriptor.
5
TXFU
0,RW
Transmit FIFO Underrun
This bit is set when transmit FIFO has underrun condition during the packet
transmission. It may happen due to the heavy load on bus, receive process
dominates in full-duplex operation, or transmit buffer unavailable before end of
packet. In this case, transmit process is placed in the suspend state and underrun
error TDES0<1> is set.
3
TXJT
0,RW
Transmit Jabber Timer Expired
This bit is set when the jabber timer expired with the transmitter is still active.
Transmit process will be aborted and placed in the stop state. It also causes transmit
jabber timeout TDES0<14> to assert.
2
TXDU
0,RW
Transmit Buffer Unavailable
Final
Version: DM9102A-DS-F03
August 28, 2000
29