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Field
Name
R/W
Description
31:0
RXSTA
R/W
Start of Receive List
This field contains the base address of the first descriptor in the receive
descriptor list. LSB bits [1:0, 2:0, or 3:0] of 32-bit, 64-bit, or 128-bit bus
width is ignored and is regarded as all zero by DMA. Therefore, these
LSB bits are read-only.
Transmit descriptor list address register (ETH_DMATXDLADDR)
Offset address: 0x1010
Reset value: 0x0000 0000
Field
Name
R/W
Description
31:0
TXSTA
R/W
Start of Transmit List
This field contains the base address of the first descriptor in the receive
descriptor list. LSB bits [1:0, 2:0, or 3:0] of 32-bit, 64-bit, or 128-bit bus
width is ignored and is regarded as all zero by DMA. Therefore, these
LSB bits are read-only.
State register (ETH_DMASTS)
Offset address: 0x1014
Reset value: 0x0000 0000
Field
Name
R/W
Description
0
TXFLG
RC_W1
Transmit Flag
Frame transmission has been completed and TXDES1[31] bit in
the first descriptor is set to 1.
1
TXSFLG
RC_W1
Transmit Stopped Flag
This bit is set when the transmission stops.
2
TXBU
RC_W1
Transmit Buffer Unavailable
This bit indicates that the host owns the next descriptor in the
transmit list and DMA cannot get it. Transmission pauses. Bit
[22:20] explains the state conversion of the transmission process.
To resume processing of the transmit descriptor, the host should
change the ownership of the descriptor by setting TXDES0 [31],
and then issue a transmit poll demand command.
3
TXJTO
RC_W1
Transmit Jabber Timeout
This bit indicates that the transmit Jabber timer times out, and the
transmission process will be terminated and in the stop state. This
will cause Jabber timeout and the TXDES0 [14] flag bit to be set.
4
RXOVF
RC_W1
Receive Overflow
This bit indicates that the receive buffer overflows during frame
receiving. If part of the frame is transmitted to the application
program, the overflow state will be set in RXDES0 [11].
5
TXUNF
RC_W1
Transmit Underflow
This bit indicates that the transmit buffer underflows during frame
transmission. Transmission is suspended and the underflow error
TXDES0 [1] is set.
6
RXFLG
RC_W1
Receive Flag
Frame receiving is completed, and the specific frame state
information is updated in the descriptor. Receive and keep
running.