.bit file not loading on usrp n210

When I download a .bit file to the N210 using JTAG and Xilinx Impact the
programmer says all is good:
// *** BATCH CMD : Program -p 1
PROGRESS_START - Starting Operation.
Maximum TCK operating frequency for this device chain: 10000000.
Validating chain…
Boundary-scan chain validated successfully.
‘1’: Programming device…
LCK_cycle = NoWait.
LCK cycle: NoWait
‘1’: Reading status register contents…
CRC error
: 0
IDCODE not validated while writing FDRI
: 0
DCM matched
: 1
status of GTS_CFG_B
: 1
status of GWE
: 1
status of GHIGH
: 1
value of VSEL pin 0
: 1
value of VSEL pin 1
: 1
value of VSEL pin 2
: 1
value of MODE pin M0
: 1
value of MODE pin M1
: 0
value of MODE pin M2
: 0
value of CFG_RDY (INIT_B)
: 1
DONEIN input from Done Pin
: 1
: 0
SYNC word not found
: 0
INFO:iMPACT:2219 - Status register values:
INFO:iMPACT - 0011 1111 1100 1100
INFO:iMPACT:579 - ‘1’: Completed downloading bit file to device.
INFO:iMPACT:188 - ‘1’: Programming completed successfully.
LCK_cycle = NoWait.
LCK cycle: NoWait
INFO:iMPACT - ‘1’: Checking done pin…done.
‘1’: Programmed successfully.
PROGRESS_END - End Operation.
Elapsed time = 13 sec.
but the .bit file isn’t actually active. I know because my changes
aren’t present and the idcode reads the old value. I can reflash with
the corresponding .bin file and cycle power and it does become active.
Is it possible the download is triggering a reload of the bit stored in
flash? Any ideas are appreciated. Thanks

I’ve only done a little FPGA work on the N210 so this is a bit of a
guess, Nick or Josh can answer better, but I would imagine you probably
need to understand how the FPGA image “bootstraps”. The N210 stores 2
FPGA images so that there is a safe image to restore from if you upload
a bad image. This is because the normal FPGA image update mechanism is
via TCP/IP and hence uses the FPGA…a chicken and egg problem as it
were. Unless you are developing an FPGA image that throws away the Ettus
boot mechanism I’d suggest sticking to the regular FPGA image update
methodology and restrict your use of JTAG to Chipscope etc.

Just hold down the “safe mode” button S2 when booting. The image
you’re loading is probably bootstrapping the production FPGA image out
of Flash.


Thanks. Looks like holding down S2 while IMPACT loads the .bit file does
make the .bit file become active. However, I can never establish
ethernet connection until cycling power. I assume the fpga is loaded but
the software isn’t running? The activity lights flash rapidly but I only

RuntimeError: LookupError: KeyError: No devices found for ----->
Device Address: