Datasheet

56F8355 Technical Data, Rev. 17
38 Freescale Semiconductor
Preliminary
4.2 Program Map
The Program memory map is located in Table 4-4. The operating mode control bits (MA and MB) in the
Operating Mode Register (OMR) control the Program memory map. At reset, these bits are set as indicated
in Table 4-2.
EXT_BOOT = EMI_MODE = 0 and cannot be changed in the 56F8355 or 56F8155.
After reset, the OMR MA bit can be changed and will have an effect on the P-space memory map, as shown
in Table 4-3. Changing the OMR MB bit will have no effect.
Table 4-2 OMR MB/MA Value at Reset
1
1. Information in shaded areas not applicable to 56F8355/56F8155.
OMR MB =
Flash Secured
State
2,3
2. This bit is only configured at reset. If the Flash secured state changes, this will not be reflected in MB until the next reset.
3. Changing MB in software will not affect Flash memory security.
OMR MA =
EXTBOOT Pin
Chip Operating Mode
0 0 Mode 0 – Internal Boot; EMI is configured to use 16 address lines; Flash Memory is
secured; external P-space is not allowed; the EOnCE is disabled
0 1 Not valid; cannot boot externally if the Flash is secured and will actually configure to 00
state
1 0 Mode 0 – Internal Boot; EMI is configured to use 16 address lines
1 1 Mode 1 – External Boot; Flash Memory is not secured; EMI configuration is
determined by the state of the EMI_MODE pin