Intel IXP42X User Manual

Page of 568
Intel
®
 IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
September 2006
DM
Order Number: 252480-006US
545
UTOPIA Level-2—Intel
®
 IXP42X product line and IXC1100 control plane processors
In cell-level single-PHY (SPHY) mode, the physical interface indicates that a cell is 
ready to be sent by asserting the UTP_IP_FCI (a.k.a. RX_EMPTY_N/RX_CLAV) signal. 
The UTOPIA Level-2 Interface on the IXP42X product line and IXC1100 control plane 
processors subsequently initiates the transfer of a cell from the physical interface by 
asserting UTP_IP_FCO (a.k.a. RX_ENB_N).
In octet-level single-PHY (SPHY) mode, the UTOPIA Level-2 Interface on the IXP42X 
product line and IXC1100 control plane processors indicate to the physical interface 
that the UTOPIA Receive interface is ready to receive bytes by asserting UTP_IP_FCO 
(a.k.a. RX_ENB_N) signal.   The physical interface indicates a valid byte is on the 
UTOPIA data bus by de-asserting UTP_IP_FCI (also known as RX_EMPTY_N/RX_CLAV) 
signal.
The Receive Module maintains various statistical counters. The statistics that can be 
maintained are on a single physical port address on a specified VPI/VCI address value. 
The 32-bit counters will maintain the following counts:
• The number of cells received
• The number of cells with an incorrect cell size
• The number of cells containing HEC errors.
• The number of idle cells received
The counters are not cleared when read by the Network Processor Engine core. The 
Network Processor Engine core must perform an explicit write to the specified register 
to clear the counter values.
There is an overflow bit per counter to indicate that the count has “rolled over.” A mask-
able interrupt mechanism is used to allow the UTOPIA Level-2 Coprocessor to flag to 
the Network Processor Engine Core that a “roll over” has occurred.
19.3
UTOPIA-2 Coprocessor / NPE Coprocessor: Bus Interface
The Network Processor Engine Coprocessor Interface Module provides the necessary 
interface logic required for configuration, monitoring, control, and test of the UTOPIA 
Level-2 coprocessor. All of the UTOPIA Level-2 coprocessor’s internal configuration and 
control registers, instruction registers, and FIFOs are directly accessible by the Network 
Processor Engine core.
Figure 99.
UTOPIA Level-2 MPHY Receive Polling
 
UTP_RX_CLK 
UTP_RX_ADDR (4:0) 
UTP_RX_FCI 
(a.k.a. – RX_CLAV) 
UTP_RX_FCO 
(a.k.a. – RX_ENB_N) 
UTP_RX_DATA(7:0) 
UTP_RX_SOC 
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