
DS33Z41 Quad IMUX Ethernet Mapper
8.10 Connections and Queues
The
The user can define the connection and the size of the transmit and receive queues. The size is adjustable in units of 32(by 2048 byte) packets. The external SDRAM can hold up to 8192 packets of data. The user must ensure that all the connection queues do no exceed this limit. The user also must ensure that the transmit and receive queues do not overlap each other. Unidirectional connections are not supported.
When the user changes the queue sizes, the connection must be torn down and
The user can also program High and Low watermarks. If the queue size grows past the High watermark, an interrupt is generated if enabled. The registers of relevance are described in Table
The Receive Queue functions in a similar manner. Note that the user must ensure that sizes and watermarks are set in accordance with the configuration speed of the Ethernet and Serial interfaces. The DS33Z41 does not provide error indication if the user creates a connection and queue that overwrites data for another connection queue. The user must take care in setting the queue sizes and watermarks. The registers of relevance are AR.RQSC1and SU.QCRLS. Queue size should never be set to 0.
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