Intel IXP2400 User Manual page 74

IXP2400/IXP2800 Network Processors
Developer Workbench
Maximum burst 1
Enable Tx flow control This check box enable Tx flow control training between the SPI4 device
Training frequency
The Default port parameters section is further divided into Receive and Transmit areas. You
may edit these characteristics, which are:
Data rate (Mbits/sec)
Receive buffer size
Receive threshold
Transmit buffer size
Low water mark
High water mark
Interpacket gap (nsec)
Number of bytes the device strips from end of packet
Number of bytes of zeros the device appends to packet
Number of extra bytes
74
This value is the maximum number of 16 byte blocks that the Tx FIFO
can accept when the FIFO Status channel indicates a "Starving"
condition.
and the network processor.
This value indicates the maximum interval (in TS clock cycles, with the
TS clock being one-fourth the Tx clock Frequency) between scheduling
of flow control training sequences.
Specifies the rate at which data is taken from the network and inserted
into the port's receive (Rx) buffer and the rate at which data is taken from
the port's transmit (Tx) buffer and put onto the network.
Specifies the number of bytes in the receive buffer. The receive buffer
holds the data received from the network until the Network Processor
reads it from the port.
Specifies number of bytes that must be in the port's receive buffer in
order for the port to signal the Network Processor that it can select the
port and request data from it.
Specifies the number of bytes in the transmit buffer. The transmit buffer
holds the data transmitted by the Network Processor until it is
transmitted onto the network.
See High water mark, below.
If flow control is enabled, the high water mark is used to determine if the
device is "Hungry" or "Satisfied". If the number of bytes in the Tx buffer
is between the low and high water marks, then the device tells the
network processor that it is Hungry. If the number of bytes is above the
high water mark, then the device tells the network processor that it is
Satisfied.
Specifies the amount of time between packets when receiving packets
from and transmitting packets to the network.
Specifies the number of bytes that the device must strip from the end of
each received packet before the packet is passed to the Network
Processor. For example, for POS IP packets, the trailing checksum bytes
are normally stripped.
Specifies the number of bytes of zeroes the device appends to the packet
before it is transmitted by the Network Processor.
Specifies the number of bytes that are stripped from the beginning of the
packet before it reaches the device and appended to the beginning of the
packet after it leaves the device, for example the Ethernet preamble.
Development Tools User's Manual