AN1176 STMicroelectronics, AN1176 Datasheet - Page 14

• Manufacturer Part Number: AN1176
• Description: 68HC11/PSD813F1 DESIGN GUIDE
• Manufacturer: STMicroelectronics

For this simple example, you can ignore the warning and click ‘OK’ because we are only placing
68HC11 code into EEPROM segments EES0 and EES1, which are not paged. But here is an
explanation of this warning, as it will apply later on if you page your firmware.
After clicking OK to the warning message, you should see this:
On the left are the individual PSD memory segments (FSO, FS1, etc). The next column holds the
logic equations for selection of each memory segment (from PSDabel) are shown for reference.
In the middle are the address ranges that you specified in the PSDabel file to create the memory
map (PSDsoft filled in these address fields for you). PSDsoft will expect to find these absolute
MCU addresses within your 68HC11 linker file(s) when the file(s) are imported. On the right are
boxes where you type in the name of the file(s) that your 68HC11 linker creates. Notice that you
can select Motorola S-Record or Intel HEX format for input. Leave the ‘Mapping Mode’ set to
‘Direct’.
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PSDsoft attempts to populate all of the address range boxes for you, based on your PSDabel
equations. These are the absolute address ranges that PSDsoft will expect to see inside the file(s)
generated by your 68HC11 linker. However, if PSDsoft sees that paging information is used in
your PSDabel memory segment equations, PSDsoft warns you it has filled in address ranges that
may be ambiguous (overlapping or dependent on non-address signals, like page register bits) and
it is up to you to resolve them. How you resolve them is purely a function of your 68HC11
compiler/linker and how it handles paging. For example, some MCU linkers will generate a
different file for each memory page of firmware, and each of these files will contain MCU
addresses that do not exceed 16 bits. Other linkers will put all of the memory pages of firmware
into a single file using MCU addresses greater than 16 bits to represent multiple pages (extends
16-bit addresses with page bits). Either method requires you to type the appropriate file name(s)
and address ranges into the window based on how your particular 68HC11 linker operates.