DP83934CVUL20 National Semiconductor, DP83934CVUL20 Datasheet - Page 22

• Manufacturer Part Number: DP83934CVUL20
• Manufacturer: National Semiconductor

Specifications of DP83934CVUL20

• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.75V
• Operating Supply Voltage (max): 5.25V
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 160
• Lead Free Status / RoHS Status: Not Compliant

3 0 Functional Description
4 0 Transmit Receive IEEE 802 3 Frame Format
A standard IEEE 802 3 packet (Figure 4-1) consists of the
following fields preamble Start of Frame Delimiter (SFD)
destination address source address length data and
Frame Check Sequence (FCS) The typical format is shown
in Figure 4-1 The packets are Manchester encoded and
decoded by the ENDEC unit and transferred serially to from
the MAC unit using NRZ data with a clock All fields are of
fixed length except for the data field The SONIC-T gener-
ates and appends the preamble SFD and FCS field during
transmission The Preamble and SFD fields are stripped
during reception (The CRC is passed through to buffer
memory during reception )
Note B
b
e
e
bits
bytes
Note The number of collisions and the contents of the Transmit Control register are posted in the TXpkt status field (see
Section 5 5 1 2) The contents of the Receive Control register are posted in the RXpkt status field (see Section 5 4 3)
Frames Transmitted OK
Single Collision Frames
Multiple Collision Frames
Collision Frames
Frames with Deferred Transmissions
Late Collisions
Excessive Collisions
Excessive Deferral
Internal MAC Transmit Error
Frames Received OK
Multicast Frames Received OK
Broadcast Frames Received OK
Frame Check Sequence Errors
Alignment Errors
Frame Lost due to Internal MAC Receive Error
Statistic
TABLE 3-1 Network Management Statistics
FIGURE 4-1 IEEE 802 3 Packet Structure
(Continued)
22
4 1 PREAMBLE AND START OF FRAME DELIMITER
(SFD)
The Manchester encoded alternating 1 0 preamble field is
used by the ENDEC to acquire bit synchronization with an
incoming packet When transmitted each packet contains
62 bits of an alternating 1 0 preamble Some of this pream-
ble may be lost as the packet travels through the network
Byte alignment is performed when the Start of Frame Delim-
iter (SFD) pattern consisting of two consecutive 1’s is de-
tected
4 2 DESTINATION ADDRESS
The destination address indicates the destination of the
packet on the network and is used to filter unwanted pack-
Register Used
RCR (Note)
RCR (Note)
RCR (Note)
TCR (Note)
TCR (Note)
TCR (Note)
TCR (Note)
TCR (Note)
TCR (Note)
(Note)
(Note)
(Note)
CRCT
FAET
RCR
RCR
MPT
ISR
PTX
NC0– NC4
NC0– NC4
NC0– NC4
DEF
OWC
EXC
EXD
BCM FU
PRX
MC
BC
All
CRC
All
FAE
All
RFO
Bits Used
TL F 11719 – 14