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MachXO2 Programming and Configuration Usage Guide
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Bitstream Generation Options
The Bitstream Generation options allow you to decide how the Diamond development tools create the configuration
data for the MachXO2 device. The CONFIGURATION, USERCODE, CUSTOM_IDCODE, and SHAREDEBRINIT
settings are saved in the Feature Row and remain in effect until the Feature Row is erased. The other options allow
you to control the JEDEC and BIT files that are generated by Diamond.
COMPRESS_CONFIG
The COMPRESS_CONFIG preference alters the way JEDEC and BIT files are generated. The
COMPRESS_CONFIG default setting is to be ON.
JEDEC files, when they are built, are always compressed. The configuration time will be slightly reduced when
reading configuration data from the external PROM and the Diamond tool will create a JEDEC file you can program
into the internal Flash memory.
CONFIGURATION
The CONFIGURATION preference allows you to control the Configuration Flash and UFM sectors. The CONFIGU-
RATION preference has four possible settings:
•
CFG
– The CFG preference is the default mode for building configuration data. The configuration bitstream is
stored in the Configuration Flash and is not permitted to overflow into the UFM sector. The configuration data
includes EBR initialization data. The UFM sector is available for your use as general purpose Flash memory in
user mode.
•
CFG_EBRUFM
– This preference creates configuration data that is stored in the Configuration Flash. EBR ini-
tialization data is stored in the lowest page addresses of the UFM sector. The UFM sector is available in user
mode. You must restore the EBR initialization data when making changes to the UFM to guarantee correct oper-
ation.
•
CFGUFM
– This preference creates configuration data that is stored in the Configuration Flash. This mode dif-
fers from CFG by allowing the configuration data to overflow into the UFM. The configuration data increases in
size as EBR initialization data is added to the design.
•
EXTERNAL
– This preference generates configuration data that is stored in an external memory. The UFM sec-
tor is available as general purpose Flash memory in user mode.
The CONFIGURATION preference defaults to the CFG state in the current release of the Diamond software. The
Diamond design software only generates JEDEC files when your entire design fits within the Configuration Flash
memory. The UFM is guaranteed to be available when the MachXO2 device enters user mode.
In the event the configuration data does not fit in the Configuration Flash memory try using the CFG_EBRUFM
preference. This preference works well if your design has a significant amount of initialized EBR, and you still want
access to UFM pages to store data. Depending on the amount of initialized EBR the UFM may still have sufficient
space available for storing your data.
Use the CFGUFM option when the Configuration Flash is not large enough to store the configuration data, and you
do not need to use UFM for storing your own data. It is possible, in rare instances, for the size of the configuration
data to exceed the combined space of the Configuration Flash and UFM.
Use the EXTERNAL preference to build configuration data for use with Master SPI Configuration Mode. When the
configuration data exceeds the combined space available in the Configuration Flash and UFM it is necessary to
switch to EXTERNAL mode. EXTERNAL mode does not use any Configuration Flash or UFM resources. The UFM
is available for your use in user mode.
The MachXO2-256 device does not contain any UFM. The only configuration options available to this device are
the CFG and EXTERNAL modes.