DP83820BVUW National Semiconductor, DP83820BVUW Datasheet - Page 20

• Manufacturer Part Number: DP83820BVUW
• Description: IC INTERFACE CONTROLLER 208-PQFP
• Manufacturer: National Semiconductor

Specifications of DP83820BVUW

• Controller Type: Ethernet Controller, MAC/BIU
• Interface: IEEE 802.3
• Voltage - Supply: 3.3V
• Current - Supply: 150mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 208-MQFP, 208-PQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *DP83820BVUW

3.0 Functional Description
19-16
24-23
bit
20
26
25
22
21
20
19
18
17
16
LONG
CRCE
CCNT
RUNT
DEST
RXO
RXA
FAE
LBP
tag
ISE
IRL
EC
Excessive Collisions
Collision Count
Receive Aborted
Receive Overrun
Destination Class
Too Long Packet
Received
Runt Packet Received
Invalid Symbol Error
CRC Error
Frame Alignment Error
Loopback Packet
In-Range Length Error
Table 3-5 Receive
(Continued)
description
cmdsts
20
The number of collisions during the transmission of this
packet was excessive, indicating transmission failure.
If TXCFG register ECRETRY=0, this bit is set after 16
collisions.
If TXCFG register ECRETRY=1, this bit is set after 4
Excessive Collision events (64 collisions).
If TXCFG register ECRETRY=0, this field indicates the
number of collisions encountered during the transmission of
this packet.
If TXCFG register ECRETRY=1,
CCNT[3:2] = Excessive Collisions (0-3)
CCNT[1] = Multiple Collisions
CCNT[0] = Single Collision
Note that Excessive Collisions indicate 16 attempts failed,
while Multiple Collisions and Single Collision indicate
collisions in addition to any excessive collisions. For
example, a collision count of 33 includes 2 Excessive
Collisions and will also set the Single Collision bit.
Set to 1 by DP83820 when the receive was aborted. If RXO
is set, then the receive was aborted due to an RX overrun. If
RXO is clear, then a receive descriptor error occurred. SIZE
will be set to the amount of data that was transferred to
memory when the error was detected.
Set to 1 by DP83820 to indicate that a receive overrun
condition occurred. RXA will also be set.
When the receive filter is enabled, these bits will indicate the
destination address class as follows:
00 - Packet was rejected
01 - Destination matched the Receive Filter Node Address
Register
10 - Destination is a multicast (but not broadcast)
11 - Destination is a broadcast address
If the Receive Filter is enabled, 00 indicates that the packet
was rejected. Normally packets that are rejected do not
cause any bus activity, nor do they consume receive
descriptors. However, this condition could occur if the packet
is rejected by the Receive Filter later in the packet than the
receive drain threshold (RXCFG:DRTH)
The size of the receive packet exceeded 1518 bytes (1522
bytes if VLAN tag included).
The size of the receive packet was smaller than 64 bytes
(including CRC).
(100 Mb only) An invalid symbol was encountered during the
reception of this packet.
The CRC appended to the end of this packet was invalid.
The packet did not contain an integral number of octets.
The packet is the result of a loopback transmission.
The receive packet Length/Type field did not match the
length of the data field for the packet. Only valid if the
Length/Type field is a valid length (not a Type value).
Bit Definitions
usage
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