Freescale Semiconductor MPC5604B - 3. Configuration

MPC5604B/C Microcontroller Reference Manual, Rev. 8
72 Freescale Semiconductor
Figure 5-6. BAM logic flow
The initial (reset) device configuration is saved including the mode and clock configuration. This means
that the serial download software running in the BAM can make changes to the modes and clocking and
then restore these to the default values before running the newly downloaded application code from the
SRAM.
The SSCM_STATUS[BMODE] field indicates which boot mode is to be executed (see Table 5-5). This
field is only updated during reset.
There are 2 conditions where the boot mode is not considered valid and the BAM pushes the
microcontroller into static mode after restoring the default configuration:
• BMODE = 011 (flash memory boot mode). This means that the SSCM has been unable to find a
valid BOOT_ID in the boot sectors so has called the BAM
• BMODE = reserved
In static mode a wait instruction is executed to halt the core.
For the FlexCAN and LINFlex serial boot modes, the respective area of BAM code is executed to
download the code to SRAM.
No
Restore default
configuration
configuration
Save default
BAM Entry
0xFFFF_C000
Boot mode valid?
Download new
code and save in
SRAM
Restore default
configuration
Execute new
code
STATIC mode
Ye s
Check boot
mode at
SSCM_STATUS[BMODE]