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PCI Bus Controller
22-38
Freescale Semiconductor
22.4.3.2
Configuration Mechanism
To support Type 0 and Type 1 configuration transactions, the PCI controller provides the 32 bit
configuration address register (PCICAR). The register specifies the target PCI bus, device, function, and
configuration register accessed. A read or a write to the PCI controller window defined as PCI I/O space
in the PCIIWCR causes the host bridge to translate the access into a PCI configuration cycle if the
PCICAR[E] bit is set and the device number does not equal 0b1_1111. For space defined as I/O space, the
accessed space (one of the initiator windows) must be programmed as I/O, not memory. See
Section 22.3.2.6, “Initiator Window Configuration Register (PCIIWCR).”
Section 22.3.2.12, “Configuration Address Register (PCICAR)”
shows the format of the PCICAR register
.
When the PCI controller detects an access to an I/O window, it checks the PCICAR[E,Device Number]
fields. If the enable bit is set, and the device number is not 0b1_1111, the PCI controller performs a
configuration cycle translation function and runs a
CONFIGURATION
READ
or
CONFIGURATION
WRITE
transaction on the PCI bus. The device number 0b1_1111 performs
INTERRUPT
ACKNOWLEDGE
and
SPECIAL
CYCLE
transactions. See
Section 22.4.3.3, “Interrupt Acknowledge Transactions,”
and
Section 22.4.3.4, “Special Cycle Transactions,”
for more information. If the bus number corresponds to
the local PCI bus (bus number equals 0x00), a Type 0 configuration cycle transaction performs. If the bus
number indicates a remote PCI bus, PCI controller performs a Type 1 configuration cycle translation. If
the enable bit is not set, access to the configuration window passes through to the PCI bus as an I/O transfer
(window translation applies).
NOTE
Size access to the window determines the PCI data byte enables
(PCI_CBE[3:0]).
22.4.3.2.1
Type 0 Configuration Translation
shows the Type 0 translation function performed on the contents of the configuration address
register to the PCI_AD[31:0] signals on the PCI bus during the address phase of the configuration cycle
(this only applies when the PCICAR[E] bit is set).
11
001
—
—
—
OP7
00
0111
OP7
—
—
—
00
010
OP6
OP7
—
—
00
1100
—
—
OP7
OP6
10
010
—
—
OP6
OP7
00
0011
OP7
OP6
—
—
00
100
OP4
OP5
OP6
OP7
00
0000
OP7
OP6
OP5
OP4
1
The byte lane translation is similar for other types of transactions. However, the PCI address
may differ from
Section 22.4.1.5, “Addressing.”
Table 22-28. Internal bus to PCI Byte Lanes for Memory
1
Transactions (continued)
Internal Bus
PCI Bus
HADDR
[1:0]
HSIZE
[2:0]
Data Bus Byte Lanes
AD
[1:0]
BE
[3:0]
Data Bus Byte Lanes
31:24 23:16
15:8
7:0
31:24 23:16
15:8
7:0
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...