mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 133

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

3.3.2.2
Read: Anytime
Write: Anytime
The global page index register is used to construct a 23 bit address in the global map format. It is only used
when the CPU is executing a global instruction (GLDAA, GLDAB, GLDD, GLDS, GLDX,
GLDY,GSTAA, GSTAB, GSTD, GSTS, GSTX, GSTY) (see CPU Block Guide). The generated global
address is the result of concatenation of the CPU local address [15:0] with the GPAGE register [22:16] (see
Figure
Freescale Semiconductor
Address: 0x0010
GP[6:0]
Reset
Field
6–0
W
R
3-7).
Bit22
LDX
MOVB
GLDAA
Global Page Index Bits 6–0 — These page index bits are used to select which of the 128 64KB pages is to be
accessed.
Global Page Index Register (GPAGE)
0
0
7
GPAGE Register [6:0]
Example 3-1. This example demonstrates usage of the GPAGE register
#0x5000
#0x14, GPAGE
X
= Unimplemented or Reserved
GP6
0
6
Figure 3-6. Global Page Index Register (GPAGE)
S12XS Family Reference Manual, Rev. 1.10
Figure 3-7. GPAGE Address Mapping
Table 3-4. GPAGE Field Descriptions
GP5
0
5
;Set GPAGE offset to the value of 0x5000
;Initialize GPAGE register with the value of 0x14
;Load Accu A from the global address 0x14_5000
Global Address [22:0]
Bit16
Bit15
GP4
0
4
Description
GP3
0
3
CPU Address [15:0]
GP2
Memory Mapping Control (S12XMMCV4)
0
2
GP1
0
1
Bit 0
GP0
0
0
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