AN2295 Freescale Semiconductor / Motorola, AN2295 Datasheet - Page 19

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

FC Protocol, Version 2, HC9S08 Implementation
This section describes features that are specific to the HC9S08 bootloader implementation. The memory
allocation is heavily MCU specific so the meaning of variables is explained in this section.
Figure 16
pre-programmed. For example, the HC9S08GB/GT60 device memory map includes:
Memory Allocation
The bootloader code occupies the top end of FLASH memory (the highest memory address space). This
placement allows an effective use of the FLASH protection technique (see the specific MCU data sheet
for details).
Freescale Semiconductor
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60 Kbytes of FLASH memory ($1080–$17FF, $182C–$FFAF)
4 Kbytes of random-access memory (RAM) ($0080–$107F)
16 bytes of nonvolatile registers ($FFB0–$FFBF)
64 bytes of user-defined vectors ($FFC0–$FFFF)
INTERRUPT VECTOR TABLE
NONVOLATILE REGISTERS
BOOTLOADER CODE
RELOCATED VECTOR TABLE
HIGH PAGE REGISTERS
FLASH 1920 BYTES
RAM
I/O REGISTERS
FLASH 58772 BYTES
shows the memory allocation typical to the HC9S08 devices with the bootloader
Figure 16. Simplified Example of Memory Allocation in MC9S08GB/GT60
Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs, Rev. 6
0xFFFF
0xFFC0
0xFFB0
0xFE00
0xFDC0
0x182C
0x1800
0x1080
0x0080
0x0000
THIS AREA OF FLASH IS PROTECTED
FLASH MEMORY AVAILABLE
FOR USER CODE
FC Protocol, Version 2, HC9S08 Implementation
FLASH MEMORY AVAILABLE
ON MC9S08GB/GT60 MCU
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