Memory Mapping Control (S12XMMCV4)
S12XS Family Reference Manual, Rev. 1.13
142
Freescale Semiconductor
3.4.2.1.1
Expansion of the Local Address Map
Expansion of the CPU Local Address Map
The program page index register in MMC allows accessing up to 4MB of FLASH or ROM in the global
memory map by using the eight page index bits to page 256 16KB blocks into the program page window
located from address 0x8000 to address 0xBFFF in the local CPU memory map.
The page value for the program page window is stored in the PPAGE register. The value of the PPAGE
register can be read or written by normal memory accesses as well as by the CALL and RTC instructions
(see
Section 3.5.1, “CALL and RTC Instructions
Control registers, vector space and parts of the on-chip memories are located in unpaged portions of the
64KB local CPU address space.
The starting address of an interrupt service routine must be located in unpaged memory unless the user is
certain that the PPAGE register will be set to the appropriate value when the service routine is called.
However an interrupt service routine can call other routines that are in paged memory. The upper 16KB
block of the local CPU memory space (0xC000–0xFFFF) is unpaged. It is recommended that all reset and
interrupt vectors point to locations in this area or to the other unpaged sections of the local CPU memory
map.
The RAM page index register allows accessing up to 1MB minus 2KB of RAM in the global memory map
by using the eight RPAGE index bits to page 4KB blocks into the RAM page window located in the local
CPU memory space from address 0x1000 to address 0x1FFF. The Data FLASH page index register
EPAGE allows accessing up to 256KB of Data Flash in the system by using the eight EPAGE index bits to
page 1KB blocks into the Data FLASH page window located in the local CPU memory space from address
0x0800 to address 0x0BFF.
Содержание MC9S12XS128
Страница 4: ...S12XS Family Reference Manual Rev 1 13 4 Freescale Semiconductor ...
Страница 58: ...Device Overview S12XS Family S12XS Family Reference Manual Rev 1 13 58 Freescale Semiconductor ...
Страница 150: ...Memory Mapping Control S12XMMCV4 S12XS Family Reference Manual Rev 1 13 150 Freescale Semiconductor ...
Страница 168: ...Interrupt S12XINTV2 S12XS Family Reference Manual Rev 1 13 168 Freescale Semiconductor ...
Страница 194: ...Background Debug Module S12XBDMV2 S12XS Family Reference Manual Rev 1 13 194 Freescale Semiconductor ...
Страница 364: ...Periodic Interrupt Timer S12PIT24B4CV1 S12XS Family Reference Manual Rev 1 13 364 Freescale Semiconductor ...
Страница 396: ...Pulse Width Modulator S12PWM8B8CV1 S12XS Family Reference Manual Rev 1 13 396 Freescale Semiconductor ...
Страница 506: ...Voltage Regulator S12VREGL3V3V1 S12XS Family Reference Manual Rev 1 13 506 Freescale Semiconductor ...
Страница 736: ...Ordering Information S12XS Family Reference Manual Rev 1 13 736 Freescale Semiconductor ...
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