Intel IXP42X Personal Computer User Manual


 
Intel
®
IXP42X product line and IXC1100 control plane processors—PCI Controller
Intel
®
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
232 Order Number: 252480-006US
implemented on the IXP42X product line and IXC1100 control plane processors. The
transaction is initiated to address location hexadecimal 0x00000015. The value of
binary 01 in PCI_AD (1:0) indicates that the transfer is a valid byte address of the first
byte of 32-bit word address 0x00000014 (0x00000014 + 0x00000001 = 0x00000015).
The byte-enables being 0xD — during the data transfer — signify that the transfer is a
byte transfer to the above-mentioned address. A hexadecimal value of 0x3 written on
the PCI_C/BE_N bus during the address phase signifies that this is a PCI Bus I/O Write
Cycle.
6.6.10 Initiated Burst Memory Read Transaction
The following transaction is a two word bursting PCI Memory Read Cycle initiated from
the IXP42X product line and IXC1100 control plane 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 IXP42X product line and IXC1100 control plane
processors. The transaction is initiated to initial address location hexadecimal
0x00000014. The value of binary 00 in PCI_AD (1:0) indicates that this is a linear
increment transfer type. The second data word transferred will be from address
hexadecimal 0x00000018.
A hexadecimal value of 0x6 — written on the PCI_C/BE_N bus during the address
phase — signifies that this is a PCI Bus Memory Read Cycle. All byte-enables are active
for the transaction.
A maximum burst length of eight 32-bit words is supported for initiated Memory Cycle
transactions from the IXP42X product line and IXC1100 control plane processors.
Figure 42. Initiated PCI I/O Write Cycle
PCI_CLK
PCI_FRAME_N
PCI_AD (31:0)
PCI_IDSEL
PCI_C/BE_N
PCI_IRDY_N
PCI_TRDY_N
PCI_DEVSEL_N
0x00000015
DAT
A
0x3 0x
D
INT_REQ_N
INT_GNT_N