mc9s12xf512 Freescale Semiconductor, Inc, mc9s12xf512 Datasheet - Page 419

• Manufacturer Part Number: mc9s12xf512
• Description: S12x Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

accessing up to 1022KB of RAM (in the Global map) within the 64KB Local map. The RAM page index
register is effectively used to construct paged RAM addresses in the Local map
The reset value of 0xFD ensures that there is a linear RAM space available between addresses 0x1000 and
0x3FFF out of reset.
The fixed 4K page from 0x2000–0x2FFF of RAM is equivalent to page 254 (page number 0xFE).
The fixed 4K page from 0x3000–0x3FFF of RAM is equivalent to page 255 (page number 0xFF).
Freescale Semiconductor
RP[7:0]
Field
7–0
RAM Page Index Bits 7–0 — These page index bits are used to select which of the 256 RAM array pages is to
be accessed in the RAM Page Window.
XGATE write access to this register during an CPU access which makes use
of this register could lead to unexpected results.
Because RAM page 0 has the same global address as the register space, it is
possible to write to registers through the RAM space when RPAGE = 0x00.
The page 0xFD (reset value) contains unimplemented area in the range not
occupied by RAM if RAMSIZE is less than 12KB (Refer to
Section 11.4.2.3, “Implemented Memory
The two fixed 4KB pages (0xFE, 0xFF) contain unimplemented area in the
range not occupied by RAM if RAMSIZE is less than 8KB (Refer to
Section 11.4.2.3, “Implemented Memory
0
0
0
MC9S12XF - Family Reference Manual, Rev.1.19
Figure 11-14. RPAGE Address Mapping
Table 11-13. RPAGE Field Descriptions
Bit19
Global Address [22:0]
Bit18
RPAGE Register [7:0]
Chapter 11 Memory Mapping Control (S12XMMCV4) SUPPORTING FLEXRAY
CAUTION
NOTE
NOTE
Description
Map).
Map).
Bit12
Address: CPU Local Address
Bit11
or BDM Local Address
Address [11:0]
format.
Bit0
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