GD32F20x User Manual
801
Jabber Timeout
When the receiving frame does not appear the following situation, it can be called ‘fine frame’
and MSC reception counters will automatically update:
Alignment error
CRC mismatch(calculated CRC value is different from FSC field value)
Runt frame (frame length is shorter than 64 bytes)
Length error (length field value is different from the actual received data bytes)
Range error (length field value is larger than maximum size of defined in
IEEE802.3,which is 1518 for untagged frame and 1522 for VLAN tagged frame)
Error signal valid on pin MII_RX_ER
Note:
Only when the discarded frame is a short frame whose length is less than 6 bytes (no
complete receives the DA), MSC reception counter is updated.
27.3.4.
Wake up management: WUM
Ethernet (ENET) module supports two wakeup methods from Deep-sleep mode. The one is
remote wakeup frame and the other is Magic Packet wakeup frame. For reduce power
consuming, the host system and Ethernet can be powered down and thus the circuit driven
by HCLK or transmit clock is stop working. But the circuit driven by receive clock will continues
working for listening wakeup frame. If application sets the PWD bit in ENET_MAC_WUM
register, the Ethernet enters into power-down state. In power-down state, MAC ignores all the
frame data on the interface until the power-down state is exited. For exiting power-down state,
application can choose one or both of the two methods mentioned above. Setting WFEN bit
in ENET_MAC_WUM register can make Ethernet wakeup if a remote wakeup frame received
and setting MPE bit in ENET_MAC_WUM register can make Ethernet wakeup if a Magic
Packet frame is received. When any type of wakeup frame is present on interface and
corresponding wakeup function is enabled, Ethernet will generate a wakeup interrupt and exit
power-down state at once.
Remote wakeup frame detection
Setting WFEN bit in ENET_MAC_WUM register can enable remote wakeup detection. When
the MAC is in power-down state and remote wakeup function enable bit is set, MAC wakeup
frame filter is active. If the received frame passes the address filter and filter CRC-16 matches
the incoming examined pattern, then MAC identified the received wakeup frame, and then
MAC returns to normal working state. Even if the length of the wakeup frame exceeds 512
bytes, as long as the frame has a correct CRC value, it is still considered to be effective. After
received the remote wakeup frame, the WUFR bit in ENET_MAC_WUM register will be set.
If remote wakeup interrupt is not masked, then a WUM interrupt is generated.
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...