Bandwidth Control Function; Send Descriptors Content - ADMtek ADM5120 Datasheet

ADM5120

3.3.13 Bandwidth control function

This is a patented feature of ADMtek.
ADM5120 can provide the RX/TX separated bandwidth control (or traffic shaping)
function, which can be programmed to 64K- bit/ 128K /256K /512K/ 1M/ 4M/ 10M.
In a fixed period, ADM5120 will count the per port RX and TX byte number, and
compare with the bandwidth control threshold. If it is over this threshold, ADM5120
will turn on the proprietary scheme to control the RX/TX behavior.

3.3.14 Send descriptors content

If CPU sends the packet to switch, either LAN or WAN, then the 'send descriptors' are
used as follows:
Bit
Type
Function Own bit ring end flag buffer1_address[24:0]
Bit
Type
Function buffer2_enable
Bit
Type
Function
Bit
Type
Function
Control
Own bit:
•
Ring end: if 1, the descriptor is the last one, the next descriptor needs to return to
•
Buffer information:
•
ADMtek Inc.
Bit[31] Bit[28]
Bit[31]
Bit[31] Bit[26:16] Bit[13:8]
append_chksum pkt-length
[10:0]
– If 0, the descriptor belongs to CPU. After the data is put in the buffer and
control bits are set, this bit will change to 1 to indicate SW can process
this packet.
– If 1, the descriptor is for SW, and after the data is taken away, then it is
loaded to SW data buffer, the bit will be then set to 0.
the base address.
– Each descriptor can support two buffers.
– The buffer address can be any byte alignment.
Bit[24:0]
control
Bit[24:0]
control
buffer2_address[24:0]
Bit[10:0]
control
buffer1_length[10:0]
Bit[5:0]
Control
force desti- To_VLAN[5:0]
port[5:0]
Function Description
Remark
Controlled by CPU
except Own-bit
Remark
Controlled by CPU
Remark
Controlled by CPU
Remark
Controlled by CPU
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