6 Configuration Mode Introduction
6.5 MSPI
UG290-2.5.2E
67(98)
6.5.3
MSPI Mode Configuration Attempts
Gowin FPGA usually support just one automatic MSPI configuration
attempt following power-up.
The GW1N(R)-9, GW2A(R)-18, and GW1NS series products are
improved:If MSPI fails to configure following power up, the device above
will automatically attempt to reconfigure.
The GW2A(R)-18 series FPGA support a total of two configuration
attempts.
GW1N (R)-9 and GW1NS FPGA support a total of three configuration
attempts.
Factors that can lead to a failed configuration include invalid device ID,
CRC failure or a false instruction.
The user can specify an alternative SPI Flash start address for the
next retry attempt when a bitstream configuration fails. This feature
reduces the risk of a configuration failure and can also be used to load a
fallback or golden image if a configuration failure occurs.
Note!
If there is an ID Code error or a bitstream header instruction error, it will not boot from
the specified SPI Flash address.
The alternative SPI Flash start address is specified using the GOWIN
EDA tool Bitstream option when running Design Place & Route (see
Multiboot for more details).
6.5.4
MULTI BOOT
MULTIBOOT refers to the FPGA reading bitstream data from different
addresses in the external Flash memory. MULTIBOOT is supported by all
FPGA devices that supports MSPI mode.
The default Flash start address following FPGA power-up is 0x0000
and this address is always used to load the initial bitstream.
The Gowin Programmer software supports the ability to write multiple
bitstreams to external Flash at different start addresses without erasing the
Flash contents.
When generating a bitstream using the GOWIN EDA tools, the user
can specify the SPI Flash start address of the next bitstream to be loaded.
I.e the current bitstream header includes a jump address to the next
bitstream location in the Flash memory.
At power-on the FPGA will automatically attempt to boot from Flash
Addr 0x0000.
If this first boot attempt fails and the FPGA device supports more than
one configuration attempt, then the next boot attempt will use the bitstream
image specified by the SPI Flash Jump Address provided in the current
bitstream header. If the next boot attempt also fails, then this process is
repeated until the total number of configuration attempts supported by the
FPGA device is exhausted.
Once the FPGA is powered-up, the RECONFIG_N input can also be
pulsed-low to prompt the jump to the next bitstream, where the SPI Flash
Jump Address is again provided in the current bitstream header. Note,