AN1177 STMicroelectronics, AN1177 Datasheet - Page 12

• Manufacturer Part Number: AN1177
• Description: P51XA-PSD8XX DESIGN GUIDE
• Manufacturer: STMicroelectronics

AN1177 - APPLICATION NOTE
file (.obj) that will later be programmed into the PSD813F2 silicon. When this process is complete, a report
will pop up that shows the resulting pin assignments PSD usage. This is the fitter report, which you can
use to document your design. Since you created a project from scratch, you might receive a fitter error. If
this is the case, you should check the PSDsoft Express User Manual for further instructions.
C Code Generation. You can take advantage of the provided low-level C code for accessing memory el-
ements within the PSD by clicking on the Generate C Code Specific to PSD box in the Design Flow win-
dow. To get the C functions and headers, specify the folder in which you want the ANSI C files to be
written. ANSI C code functions and headers are generated for you to paste into your P51XA C compiler
environment in the folder you specify. Simply tailor the code to meet your system needs. See the PSDsoft
Express User Manual for details on the C code generation feature.
Merge MCU Firmware with PSD. Now that the fitting process is complete, PSDsoft Express has created
a fuse pattern that reflects the PSD configuration and logic of your design. PSDsoft Express places this
fuse information into a file (the .obj file). However this fuse pattern does not yet contain the P51XA firm-
ware. The next step will accomplish this, producing an .obj file that contains the PSD configuration and the
P51XA firmware. This final .obj file is what gets programmed into the PSD. The same .obj file is appended
with MCU firmware in the next step below.
For this step, “Merge MCU Firmware with PSD”, you will input the firmware file(s) that contain absolute
addresses from your P51XA compiler/linker in Intel Hex format. The Merger will map these file(s) into the
memory segments of the PSD according to the chip select equations that you entered in the Design As-
sistant. This mapping process translates the absolute system addresses that P51XA uses into physical
internal PSD addresses that are used by a programmer to program the PSD. The address translation pro-
cess is transparent. All you need to do is enter the file(s) that were generated from your P51XA linker into
the appropriate boxes and PSDsoft Express does the rest.
Go to the design flow window and click the Merge MCU Firmware with PSD box and you should see this:
The far left column contains individual PSD memory segments. The next column shows the logic equa-
tions for selection of each memory segment (shown for reference only). In the middle are the address
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