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Tandem PROM - Need help

Posts: 18
Registered: ‎11-26-2016

Tandem PROM - Need help



I successfully generated a tandem PROM bitstream.

When the kintex ultrascale device is configured straight from Vivado with it, everything works fine.

Also when the tandem bitstream is separated in Stage 1 and Stage 2 using:


set_property HD.TANDEM_BITSTREAMS SEPARATE [current_design]


the workflow "Load Stage 1 -> Reboot -> Load Stage 2 -> Use Design" works fine.


However, loading it from an external n25q256 flash does not work. It seems like only the Stage 1 is loaded, because loading Stage 2 during runtime makes everything work again.
The hardware (and configurations) is ok i guess, since the PROM FPAG configuration process works fine when tandem is deactivated and the XDC is basically the same (except for the CONFIG_MODE parameter):


set_property BITSTREAM.CONFIG.CONFIGRATE 33 [current_design]
set_property CONFIG_VOLTAGE 3.3 [current_design]
set_property CFGBVS VCCO [current_design]
set_property CONFIG_MODE {SPIx4} [current_design]
set_property BITSTREAM.CONFIG.SPI_32BIT_ADDR YES [current_design]
set_property BITSTREAM.CONFIG.SPI_BUSWIDTH 4 [current_design]
set_property BITSTREAM.CONFIG.SPI_FALL_EDGE YES [current_design]


The mode pins are set to SPI-Mode. Stage 1 contains Bank 0 and 65. sys_reset is configured to use a pullup.

The MCAP interface is disabled and the mcap_design_switch unused. ICAP is also not used.


cap_gnt <= '0';
cap_rel <= '1';


How I generate the bin file


write_cfgmem -force -format bin -size 32 -interface SPIx4 -loadbit "up 0x0 input.bit" output.bin


After "Boot from Configuration Memory Device" + Reboot of the System




 It seems like something is stopping the Stage 2 stream from beeing successfully loaded. Or could it be a reset problem?

Hope somebody can point me in the right direction,



Posts: 1,229
Registered: ‎01-15-2008

Re: Tandem PROM - Need help

tandem prom with spi is having an issue in 2016.4 vivado. This is fixed in 2017.1 which is released


Posts: 18
Registered: ‎11-26-2016

Re: Tandem PROM - Need help

Hmm, even now that I know, I cannot seem to find any report about this issue and it is also not listed in 2017.1 resolved issus. 
Can you please post the source.