RM0008 Ethernet (ETH): media access control (MAC) with DMA controller
Doc ID 13902 Rev 12 997/1096
Bits 5, 7, and 0 reflect the conditions discussed in Ta ble 2 1 3 .
Bit 3 RE: Receive error
When set, this bit indicates that the RX_ERR signal is asserted while RX_DV is asserted during
frame reception.
Bit 2 DE: Dribble bit error
When set, this bit indicates that the received frame has a non-integer multiple of bytes (odd
nibbles). This bit is valid only in MII mode.
Bit 1 CE: CRC error
When set, this bit indicates that a cyclic redundancy check (CRC) error occurred on the
received frame. This field is valid only when the last descriptor (RDES0[8]) is set.
Bit 0 PCE: Payload checksum error
When set, it indicates that the TCP, UDP or ICMP checksum the core calculated does not
match the received encapsulated TCP, UDP or ICMP segment’s Checksum field. This bit is also
set when the received number of payload bytes does not match the value indicated in the
Length field of the encapsulated IPv4 or IPv6 datagram in the received Ethernet frame.
Table 213. Receive descriptor 0
Bit 5:
frame
type
Bit 7: IPC
checksum
error
Bit 0: payload
checksum
error
Frame status
00 0
IEEE 802.3 Type frame (Length field value is less than
0x0600.)
1 0 0 IPv4/IPv6 Type frame, no checksum error detected
10 1
IPv4/IPv6 Type frame with a payload checksum error (as described
for PCE) detected
11 0
IPv4/IPv6 Type frame with an IP header checksum error (as
described for IPC CE) detected
11 1
IPv4/IPv6 Type frame with both IP header and payload checksum
errors detected
00 1
IPv4/IPv6 Type frame with no IP header checksum error and the
payload check bypassed, due to an unsupported payload
01 1
A Type frame that is neither IPv4 or IPv6 (the checksum offload
engine bypasses checksum completely.)
01 0Reserved
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