Espressif ESP32 Technical Reference Manual page 234

10 Ethernet Media Access Controller (MAC)
Parameter name:
PM: Pass All Multicast
SAF: Source Address Filtering
SAIF: Source Address Inverse Filtering
10.4.6 Good Transmitted Frames and Received Frames
A frame successfully transmitted is considered a "good frame". In other words, a transmitted frame is considered
to be good, if the frame transmission is not aborted due to the following errors:
• Jabber timeout
• No carrier or loss of carrier
• Late collision
• Frame underflow
• Excessive deferral
• Excessive collision
The received frames are considered "good frames", if there are not any of the following errors:
• CRC error
• Runt frames (frames shorter than 64 bytes)
• Alignment error (in 10/100 Mbps modes only)
• Length error (non-type frames only)
• Frame size over the maximum size (for non-type frames over the maximum frame size only)
• MII_RXER input error
The maximum frame size depends on the frame type:
• The maximum size of untagged frames = 1518 bytes
• The maximum size of VLAN frames = 1522 bytes
10.5 EMAC_MTL (MAC Transaction Layer)
The MAC Transaction Layer provides FIFO memory to buffer and regulates the frames between the application
system memory and the MAC. It also enables the data to be transmitted between the application clock domain
and the MAC clock domains. The MTL layer has two data paths, namely the Transmit path and the Receive
path. The data path for both directions is 32-bit wide and operates with a simple FIFO protocol.
10.6 PHY Interface
The DMA and the Host driver communicate through two data structures:
• Control and Status Registers (CSR)
• Descriptor lists and data buffers
For details please refer to
Espressif Systems
Parameter setting:
1: Set
0: Cleared
X: Don't care
Register Summary and Linked List
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Descriptors.
234 ESP32 TRM (Version 5.2)