PXD10RM Datasheet, PDF (165/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

6.5.4.2 BAM software flow
With reference to Figure 6-4 a description of BAM logic flow is done.
BAM
entry
0xFFFF_C000
Save default
configuration
check boot
mode
Which boot mode is selected is verified
by reading the SSCM_STATUS
register (BMODE and ABD)
boot mode
valid?
NO
restore
default
configuration
STATIC mode
YES
download new code
and save it into
SRAM
restore
default
configuration
execute new
code
Figure 6-4. BAM logic flow
The first action is to save the initial device configuration. In this way is possible to restore the initial
configuration after downloading the new code but before executing it. This allows the new code being
executed as the device was just coming out of reset.
The BMODE and ABD fields of the SSCM STATUS register (see Section 38.2.2.1, System Status Register
(STATUS)) indicate which boot has to be executed (see Table 6-5).
If BMODE field shows either a single-chip value (011) or the reserved values, the boot mode is not
considered valid and the BAM pushes the device into static mode.
In all other cases the code of the relative boot is called. Data is downloaded and saved into proper SRAM
location.
PXD10 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
6-7
Preliminary—Subject to Change Without Notice