www.geehy.com Page 579
Field
Name
R/W
Description
1
TXFCTRLEN
R/W
Transmit Flow Control Enable
In full-duplex mode, when this bit is set, MAC will enable the flow
control operation to transmit the pause frame. When this bit is reset,
the flow control operation of MAC will be disabled, and MAC will not
transmit any pause frame.
In half-duplex mode, when this bit is set, the MAC will enable back
pressure operation.
When this bit is reset, the back pressure characteristic will be
disabled.
2
RXFCTRLEN
R/W
Receive Flow Control Enable
When this bit is set, the MAC will decode the received pause frame
and disable its transmitter within the specified pause time.
When this bit is reset, the decoding function of the pause frame will
be disabled.
3
UNPFDETE
R/W
Unicast Pause Frame Detect
When this bit is set, the MAC uses the unique multicast address to
detect the pause frames, and also uses the specified unicast
address in the MAC_ADDR0H and MAC_ADDR0L registers to
detect the pause frame.
When this bit is reset, the MAC only detects the pause frame of the
unique multicast address specified in the 802.3x standard.
5:4
PTSEL
R/W
Pause Threshold Select
Set the threshold of Pause timer for automatic retransmission of
pause frames. The threshold should always be less than the pause
time configured by bit [31:16]. For example, if PT = 100H (256 slot
time) and PTSEL =01, and the second PAUSE frame is initiated at
228 (256-28) slot time after the first PAUSE frame is transmitted, the
second Pause frame will be automatically transmitted.
Select the threshold
00: Pause time - 4-slot time
01: Pause time - 28-slot time
10: Pause time - 144-slot time
11: Pause time - 256-slot time
The slot time is defined as the time that the MII interface takes to
transmit 512 bits (64 bytes)
6
Reserved
7
ZQPDIS
R/W
Zero-quanta Pause Disable
When this bit is set, it is disabled to automatically generate zero-
range pause control frame when the flow control signal of FIFO layer
fails.
When this bit is reset, normal operation of automatic zero-range
pause control frame generation is enabled.
15:8
Reserved
31:16
PT
R/W
Pause Time
This bit saves the value used in the transmission of control frame. If
this bit is configured to be double synchronized to the MII clock
domain, continuous write operations should be performed on the
register only after at least 4 clock cycles in the target clock domain.