Freescale Semiconductor KIT912F634EVME Evaluation Kit KIT912F634EVME KIT912F634EVME Datenbogen
Produktcode
KIT912F634EVME
Functional Description and Application Information Memory
Mapping Control (S12SMMCV1)
MM912F634
Freescale Semiconductor
180
Figure 50. Direct Address Mapping
Example 1. This Example Demonstrates Usage of the Direct Addressing Mode
MOVB
#0x80,DIRECT
;Set DIRECT register to 0x80. Write once only.
;Global data accesses to the range 0xXX_80XX can be direct.
;Logical data accesses to the range 0x80XX are direct.
;Global data accesses to the range 0xXX_80XX can be direct.
;Logical data accesses to the range 0x80XX are direct.
LDY
<00
;Load the Y index register from 0x8000 (direct access).
;< operator forces direct access on some assemblers but in
;many cases assemblers are “direct page aware” and can
;automatically select direct mode.
;< operator forces direct access on some assemblers but in
;many cases assemblers are “direct page aware” and can
;automatically select direct mode.
Table 243. DIRECT Field Descriptions
Field
Description
7–0
DP[15:8]
Direct Page Index Bits 15–8 — These bits are used by the CPU when performing accesses using the direct addressing mode.
The bits from this register form bits [15:8] of the address (see
The bits from this register form bits [15:8] of the address (see
).
Bit15
Bit0
Bit7
CPU Address [15:0]
Bit8
DP [15:8]
Bit16
Bit17
Global Address [17:0]