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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—PCI Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Develepor’s Manual
August 2006
514
Order Number: 306262-004US
10.2.7.3
Initiated Type-1 Read Transaction
The following transaction is a PCI Configuration Read Cycle initiated from the IXP45X/
IXP46X network processors. This diagram is to understand the inner workings of PCI
transfers and may not reflect actual operation of the PCI Controller implemented on the
IXP45X/IXP46X network processors. The transaction is initiated to PCI bus segment 0,
Device number 0, Function 0, and Base Address Register 0.
This configuration cycle is a Type 1 configuration cycle and is intended for another PCI
bus segment. Binary 01 being located in bits 1:0 of the PCI_AD bus during the address
phase denotes a Type 1 PCI Configuration cycle.
A hexadecimal value of 0xA — written on the PCI_CBE_N bus during the address phase
— signifies that this is a PCI Bus Configuration Read Cycle. Due to the fact that the
access is on another PCI Bus Segment, the PCI_TRDY_N signal may take longer to
respond and therefore may be extended by several clocks and is not shown here.
Figure 81.
Initiated PCI Type-0 Configuration Write Cycle
B4283-01
PCI_CLK
INT_REQ _N
INT_GNT_N
PCI_FRAME_N
PCI_AD (31:0)
PCI_IDSEL
PCI_CBE_N
PCI_IRDY_N
PCI_TRDY_N
PCI_DEVSEL_N
DA TA
0x0
0x00000010
0x B