Maxim Integrated DS33R11 - Manual (Page 143)

DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver
143 of 344
11.3 Arbiter Registers
The Arbiter manages the transport between the Ethernet port and the Serial Interface. It is responsible for queuing
and dequeuing data to an external SDRAM. The arbiter handles requests from the HDLC and MAC to transfer data
to/from the SDRAM. The base address of the Arbiter register space is 0040h.
11.3.1 Arbiter Register Bit Descriptions
Register Name:
AR.RQSC1
Register Description: Arbiter Receive Queue Size Connection
Register Address: 40h
Bit
# 7 6 5 4 3 2 1 0
Name RQSC7 RQSC6 RQSC5 RQSC4 RQSC3 RQSC2 RQSC1 RQSC0
Default
0 0 1 1 1 1 0 1
Bits 0-7: Receive Queue Size (RQSC[0:7]) These 7 bits of the size of receive queue associated with the
connection. Receive queue is for data arriving from the MAC to be sent to the WAN. The Queue address size is
defined in increments of 32 x 2048 bytes. The queue size is AR.RQSC1 multiplied by 32 to determine the number
of 2048 byte packets that can be stored in the queue. This queue is constructed in the external SDRAM. Note:
Queue size of 0 is not allowed and should never be set.
Register Name: AR.TQSC1
Register Description: Arbiter Transmit Queue Size Connection 1
Register Address: 41h
Bit #
7 6 5 4 3 2 1 0
Name TQSC7 TQSC6 TQSC5 TQSC4 TQSC3 TQSC2 TQSC1 TQSC0
Default
0 0 0 0 0 0 1 1
Bits 0-7: Transmit Queue Size (TQSC[0:7]) This is size of transmit queue associated with the connection. The
queue address size is defined in increments of 32 packets. The range of bytes will depend on the external SDRAM
connected to the DS33R11. Transmit queue is the data queue for data arriving on the WAN that is sent to the
MAC. Note that queue size of 0 is not allowed and should never be set.