MC9S12P128 Datasheet, PDF (117/564 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

S12P Memory Map Control (S12PMMCV1)
3.5 Implemented Memory in the System Memory Architecture
Each memory can be implemented in its maximum allowed size. But some devices have been defined for
smaller sizes, which means less implemented pages. All non implemented pages are called unimplemented
areas.
• Registers has a fixed size of 1KB, accessible via xbus0.
• SRAM has a maximum size of 11KB, accessible via xbus0.
• D-Flash has a fixed size of 4KB accessible via xbus0.
• P-Flash has a maximum size of 224KB, accessible via xbus0.
3.5.1 Implemented Memory Map
The global memory spaces reserved for the internal resources (RAM, D-Flash, and P-Flash) are not
determined by the MMC module. Size of the individual internal resources are however fixed in the design
of the device cannot be changed by the user. Please refer to the SoC Guide for further details. Figure 3-11
and Table 3-8 show the memory spaces occupied by the on-chip resources. Please note that the memory
spaces have fixed top addresses.
Table 3-8. Global Implemented Memory Space
Internal Resource
Bottom Address
Registers
0x0_0000
System RAM
RAM_LOW =
0x0_4000 minus RAMSIZE⁽¹⁾
D-Flash
0x0_4400
P-Flash
PF_LOW =
0x4_0000 minus FLASHSIZE⁽²⁾
1. RAMSIZE is the hexadecimal value of RAM SIZE in bytes
2. FLASHSIZE is the hexadecimal value of FLASH SIZE in bytes
Top Address
0x0_03FF
0x0_3FFF
0x0_53FF
0x3_FFFF
In single-chip modes accesses by the CPU12 (except for firmware commands) to any of the
unimplemented areas (see Figure 3-11) will result in an illegal access reset (system reset). BDM accesses
to the unimplemented areas are allowed but the data will be undefined.
No misaligned word access from the BDM module will occur; these accesses are blocked in the BDM
module (Refer to BDM Block Guide).
S12P-Family Reference Manual, Rev. 1.12
Freescale Semiconductor
117