The
following Readback properties are available for the
Generate
Programming File process for FPGA devices. Readback is the
process of reading back data from the FPGA device to verify that the
design was downloaded properly.
- Security
Specifies the design security by selecting whether or not to allow
the readback and reconfiguration of the device. After the FPGA design
has been configured, the FPGA configuration data can be read back
and compared with the original configuration data. Also, the device
can be reconfigured with a different bitstream. For increased design
security, select either Disable Readback or Disable Readback and Reconfiguration. Select a Readback
option from the drop-down list.
- Enable Readback and Reconfiguration
Enables the readback and reconfiguration of data.
- Disable Readback
Disables readback. Use this option for design security. By disabling
readback, configuration data is secure from being read from the FPGA.
- Disable Readback and Reconfiguration
Disables both readback and reconfiguration. Use this option for
design security. By disabling readback and reconfiguration, configuration
and reconfiguration data is secure from being read from the FPGA.
By default, this property is set to Enable Readback and Reconfiguration.
- Create Readback Data Files
Specifies whether or not to create readback data files. The
readback files represent the bitstream necessary to perform readback.
The following files are created:
- RBA file – an ASCII file that contains readback commands.
- RBB file – a binary file that contains readback commands.
- RBD file – an ASCII file that contains only expected readback
data, including pad words and frames. No commands are included.
- MSD file – an ASCII file that contains only mask information
for verification, including pad words and frames. No commands are
included.
By default, this property is set to False (checkbox is
blank), and the readback data files are not generated.
- Allow SelectMAP Pins to Persist
Note The Allow SelectMAP Pins to Persist property is only available
when the Create Readback Data Files property is set to True (checkbox
is checked).
When this property is set to True (checkbox
is checked), the SelectMAP pins on the device persist as configuration
pins after configuration is completed, and the verify operation uses
these pins to read back the data, if the mode pins are set to SelectMAP.
When this property is set to False (checkbox is blank), the SelectMAP pins
only function as configuration pins during the configuration process,
and become User-I/O after configuration completes.
By default,
this property is set to False (checkbox is blank).
- Create Logic Allocation File
Note The Create Logic Allocation Files property is only available
when the Create Readback Data Files property is set to True (checkbox
is checked).
Specifies whether or not to create a logic allocation
file (design_name.ll) for your design. The
logic allocation file indicates the bitstream position of latches,
flip-flops, IOB inputs and outputs, and the bitstream position of
LUT programming and BlockRAMs. The iMPACT tool uses the design_name.ll file to locate signal values inside a readback
bitstream.
By default, this property is set to False (checkbox
is blank), and this file is not created.
- Create Mask File
Note The Create Mask File property is only available when the
Create Readback Data Files property is set to True (checkbox is checked).
Specifies whether or not to create a mask file (design_name.msk). The mask file is used to determine which bits in the bitstream
should be compared to readback data for verification purposes.
By default, the property is set to False (checkbox is blank),
and a mask file is not created.
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