Functional Description
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
15-7
Figure 15-2. Burst Read Example
During the turnaround-cycle following the address phase, the
PCI_C/BE[3–0]
signals indicate
which byte lanes are involved in the data phase. The turnaround-cycle must be enforced by the
target with the
PCI_TRDY
signal if using fast
PCI_DEVSEL
assertion. The earliest the target can
provide valid data is one cycle after the turnaround-cycle. The target must drive the
AD[31–0]
signals when
PCI_DEVSEL
is asserted except during the turnaround-cycle.
The data phase completes when data is transferred, which occurs when both
PCI_IRDY
and
PCI_TRDY
are asserted on the same clock edge. When either is deasserted a wait cycle is inserted
and no data is transferred. To indicate the last data phase
PCI_IRDY
must be asserted when
PCI_FRAME
is deasserted.
A write transaction starts when
PCI_FRAME
is asserted for the first time and the
PCI_C/BE[3–0]
signals indicate a write command. Figure 15-3 shows an example of a single beat write
transaction.
Figure 15-3. Single Beat Write Example
Figure 15-4 shows an example of a burst write transaction.
ADDR
CMD
PCI_CLK
PCI_AD[31–0]
PCI_C/BE[3–0]
PCI_FRAME
PCI_IRDY
PCI_DEVSEL
PCI_TRDY
DATA2
DATA1
BYTE ENABLES 2
BYTE ENABLES 1
ADDR
CMD
PCI_CLK
PCI_AD[31–0]
PCI_C/BE[3–0]
PCI_FRAME
PCI_IRDY
PCI_DEVSEL
PCI_TRDY
DATA
BYTE ENABLES
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 ...