Spi Flash Prom Select Jumpers (J1) - Xilinx Spartan-3A User Manual

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SPI Flash PROM Select Jumpers (J1)

The J1 jumper block, shown in
the FPGA for Master SPI mode configuration and which is optionally available via a
separate, second SPI slave select signal.
Table 12-2
PROMs during Master SPI configuration mode. The jumpers are designed so that there can
be no conflict.
•
•
Table 12-2: SPI Flash PROM Select Jumper Settings
Spartan-3A/3AN Starter Kit Board User Guide
UG334 (v1.0) May 28, 2007
indicates how the FPGA's CSO_B signal is steered to one of the SPI Flash
If both jumpers are inserted and oriented vertically, then the FPGA configures from
the Atmel SPI Flash PROM. After configuration, the FPGA application selects the
Atmel PROM using the SPI_SS_B signal and the STMicro PROM using the ALT_SS_B
signal.
If both jumpers are inserted and oriented horizontally, then the FPGA configures from
the STMicro SPI Flash PROM. After configuration, the FPGA application selects the
STMicro PROM using SPI_SS_B signal and the Atmel PROM using the ALT_SS_B
signal.
Jumper J1 SPI Mode
Setting Configuration Source
J1
AT45DB161D
J1
STMicro
M25P16
J1
AT45DB161D
J1
STMicro
M25P16
J1
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SPI Flash PROM Select Jumpers (J1)
Figure 12-1, defines which SPI Flash PROM is connected to
Atmel AT45DB161D
Slave Select Signal
Atmel SPI_SS_B
(Y4)
N/A
Atmel SPI_SS_B
(Y4)
ALT_SS_B
(Y5)
None None
After Configuration
STMicro M25P16
Slave Select Signal
N/A
SPI_SS_B
(Y4)
ALT_SS_B
(Y5)
SPI_SS_B
(Y4)
None
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