AN2295 Freescale Semiconductor / Motorola, AN2295 Datasheet - Page 21

• Manufacturer Part Number: AN2295
• Description: Developers Serial Bootloader for M68HC08 and HCS08 MCUs
• Manufacturer: Freescale Semiconductor / Motorola

FC Protocol, Version 2, HC9S08 Implementation
S19 File
Because bootloader operation must be transparent to the user S19 file, another piece of intelligence is
built into the PC master code (instead of the MCU slave). If the record in the interrupt vector table is
detected in the user S19 file, the vector is relocated into the corresponding area in the relocated interrupt
vector table. For example, if the user S19 file contains #2 interrupt vector at address $FFEA, such a vector
is relocated to the $FDEA address in the relocated interrupt vector table.
Using this method, the user S19 file does not need to be modified, but the lower address of the end of
FLASH memory must be considered.
Figure 17
illustrates HC9S08 interrupt vector table relocation.
Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs, Rev. 6
Freescale Semiconductor
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