MSC8144E Reference Manual, Rev. 3
15-12
Freescale
Semiconductor
PCI
15.1.8.3.4 Configuration Access
The PCI responds to remote host generated PCI configuration accesses to the PCI interface. This
is indicated by decoding the configuration command along with the VCOP's IDSEL being
asserted. A remote host can use PCI Configuration access to address the 256-byte PCI
configuration area within the VCOP.
15.1.8.3.5 Special Cycle Command
A special cycle command contains no explicit destination address but is broadcast to all PCI
agents. Each receiving agent must determine whether the message is applicable to itself. No
assertion of
PCI_DEVSEL
in response to a special cycle command is necessary.
A special cycle command is like any other bus command in that it has an address phase and a data
phase. The address phase starts like all other commands with the assertion of
PCI_FRAME
and
completes when
PCI_FRAME
and
PCI_IRDY
are deasserted. Special cycles terminate with an
initiator-abort. (In the special cycle case, the received-initiator-abort bit in the configuration
status register is not set.)
The address phase contains no valid information other than the command field. Even though
there is no explicit address, the address/data lines are driven to a stable state and parity is
generated. During the data phase, the address/data lines contain the message type and an optional
data field. The message is encoded on the sixteen least-significant bits (AD[15-0]). The data field
is encoded on AD[31-16]. When running a special cycle, the message and data are valid on the
first clock
PCI_IRDY
is asserted.
When the CONFIG_ADDRESS register gets written with a bus number of 0x00, the device
number is all ones, the function number is all ones and the register number is zero, the next time
the CONFIG_DATA register is accessed the VCOP does either a special cycle or an interrupt
acknowledge command. When the CONFIG_DATA register is written, the VCOP generates a
special cycle encoding on the command/byte enable lines during the address phase, and drives
the data from the CONFIG_DATA register onto the address/data lines during the first data phase.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...