TXC-06880BIOG Transwitch Corporation, TXC-06880BIOG Datasheet - Page 65

• Manufacturer Part Number: TXC-06880BIOG
• Manufacturer: Transwitch Corporation

Specifications of TXC-06880BIOG

• Operating Supply Voltage (typ): 1.8/3.3V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

PRELIMINARY TXC-06880-MB, Ed. 4
February 2005
6.2.2 Egress FIFO Operations
6.2.2.1 Egress FIFO Write:
Each Egress FIFO is 3.2 KBytes deep in SMII mode, 32 KBytes deep in GMII mode, and 12.4
KBytes deep in extended SMII mode. The Link or PHY layer device (depending on the mode
the Envoy-CE2 is in) is responsible for selecting the channel into which the frame data is
written. The Egress FIFO backpressures the SPI-3 input interface when the FIFO becomes
near full. The near full indication level is programmable as number of bytes from the FIFO full.
If the Link or PHY layer device attempts to overflow the Egress FIFO when it is configured in
Store and Forward mode, the complete frames being received are discarded and a count of
the discarded frames are provided per channel. If the Link or PHY layer device attempts to
overflow the Egress FIFO when it is configured in Streaming mode, the current frame being
received is truncated and will be sent out the targeted Ethernet port as an errored frames. All
subsequently arriving frames are discarded until some room is freed up in the Egress FIFO
and a count of the discarded frames are provided per channel.
Note: The discard frame count is used to count frames discarded due to an Egress FIFO
overflow condition and the SPI-3 Error pin assertion condition.
- Operation -
Envoy-CE2 Device
DATA SHEET
TXC-06880
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