24
Preliminary datasheet
Version: DM9102D-DS-P02
Jan. 14, 2005
0 1 1 Move data from host memory to transmit FIFO
1 0 0 Close descriptor by clearing owner bit of descriptor
1 0 1 Waiting end of transmit
1 1 0 Transmit end and Close descriptor by writing status
1 1 1 Transmit process suspend
Receive Process State
These bits are read only and used to indicate the state of receive process. The
mapping table is shown below
Bit19 Bit18 Bit17 Process State
0 0 0 Receive process stopped
0 0 1 Fetch receive descriptor
0 1 0 Wait for receive packet under buffer available
0 1 1 Move data from receive FIFO to host memory
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 received FIFO
because of the unavailable received buffer
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
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), SBE (bit13).
Reserved
System Bus Error
The PCI system bus errors will set this bit. The type of system bus error is shown in
CR5<25:23>.
Reserved
Receive Watchdog Timer Expired
This bit is set to indicate that the receive watchdog timer has expired
Receive Process Stopped
This bit is set to indicate that the receive process enters the stopped state.
Receive Buffer Unavailable
This bit is set when the DM9102D 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.
Receive Complete Interrupt
This bit is set when a received frame is fully moved into host memory and receive
status has been written todescriptor. Receive process is still running and continues to
fetch next descriptor.
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, cause 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.
Reserved
Transmit Jabber Expired
This bit is set when the transmitted data is over 2048 byte
19:17
RXPS
000,RO
16
NIS
0,RW
15
AIS
0,RW
14
13
Reserved
SBE
0,RO
0,RW
12:10
9
Reserved
RXWT
0,RO
0,RW
8
RXPS
0,RW
7
RXDU
0,RW
6
RXCI
0,RW
5
TXFU
0,RW
4
3
Reserved
TXJT
0,RO
0,RW