Maxim Integrated DS33R11 - Manual (Page 52)

DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver
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It is recommended that the user reset the queue pointers for the connection after disconnection. The pointers must
be reset before a connection is made. If this disconnect/connect procedure is not followed, incorrect data may be
transmitted. The proper procedure for setting up a connection follows:
• Set up the queue sizes for both transmit and receive queue ( AR.TQSC1 and AR.RQSC1 ).
• Set up the high/low thresholds and interrupt enables if desired ( GL.TRQIE , LI.TQTIE , SU.QRIE ).
• Reset all the pointers for the connection desired ( GL.C1QPR ).
• Set up the connections ( GL.CON1 ).
• If a connection is disconnected, reset the queue pointers after the disconnection.
Table 9-3. Registers Related to Connections and Queues
REGISTER FUNCTION
GL.CON1
Enables connection between the Ethernet Interface and the Serial Interface. Note that once
connection is set up, then the queues and thresholds can be setup for that connection.
AR.TQSC1 Size for the Transmit Queue in Number of 32—2K packets.
AR.RQSC1 Size for the Receive Queue in Number of 32—2K packets.
GL.TRQIE Interrupt enable for items related to the connections at the global level
GL.TRQIS Interrupt enable status for items related to the connections at the global level
LI.TQTIE Enables for the Transmit queue crossing high and low thresholds
LI.TQCTLS Latched status bits for connection high and low thresholds for the transmit queue.
SU.QRIE Enables for the receive queue crossing high and low thresholds
SU.QCRLS Latched status bits for receive queue high and low thresholds.
GL.C1QPR Resets the connection pointer.
9.12 Arbiter
The Arbiter manages the transport between the Ethernet port and the Serial port. It is responsible for queuing and
dequeuing packets to a single external SDRAM. The arbiter handles requests from the HDLC and MAC to transfer
data to and from the SDRAM.