Revision 1.02 – June 27, 2006
S5935 – PCI Product
Data Book
Additional Status/Control Signals for Add-On Initi-
ated Bus Mastering
Inputs:
EQ (7) AMWEN
If a serial non-volatile memory is used to configure the
S5935, and the device is configured for Add-On initi-
ated bus mastering, two additional FIFO status signals
and four additional control signals are available to the
Add-On interface. The FRF and FWE outputs provide
additional FIFO status information. Inputs FRC#,
FWC#, AMREN, and AMWEN provide additional FIFO
control. Applications may use these signals to monitor/
control FIFO flags and PCI bus requests. These new
signals are some of the lines that were used for byte-
wide nvram interface, but now are reconfigured. The
reconfigured lines are as follows:
Add-On bus Mastering Write ENable: This input is
driven high to enable bus master writes.
EQ (6) AMREN
Add-On bus Mastering Read ENable: This input is
driven high to enable bus master reads.
EQ (5) FRC#
FIFO Read Clear: This line is driven low to clear the
PCI to Add-On FIFO.
EQ (4) FWC#
FIFO Write Clear: This line is driven low to clear the
Add-On to PCI FIFO.
Outputs:
E_ADDR (15) FRF
FRF (PCI to Add-On FIFO full) and FWE (Add-On to
PCI FIFO empty) supplement the RDEMPTY and
WRFULL status indicators. These additional status
outputs provide additional FIFO status information for
Add-On FIFO control logic.
FIFO Read Full: Indicates that the PCI to Add-On
FIFO is full.
E_ADDR (14) FWE
FIFO Write Empty: Indicates the last Add-On to PCI
FIFO. Data has transferred to a final buffer and is
queued for transfer, FIFO is empty.
Figure 79. Synchronous FIFO Register Burst RDFIFO# Access Example
FIFO Pointer Advances
BPCLK
Data 0
Data 1
Data 2
DQ[31:0]
RDFIFO#
Status Before Read
New Status
New Status
RDEMPTY
144
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