MC9RS08KA2_08 Datasheet, PDF (34/136 Pages) Freescale Semiconductor, Inc – RS08 Microcontrollers

Chapter 4 Memory
14-bit memory address
Start address of memory block selected
000000
AD[13:6]
Figure 4-6. Memory Block Boundary Selector
Table 4-5 shows the memory block to be accessed through paging window ($00C0–$00FF).
Table 4-5. Paging Window for $00C0–$00FF
Page
$00
$01
$02
$03
$04
.
.
.
$FE
$FF
Memory Address
$0000–$003F
$0040–$007F
$0080–$00BF
$00C0–$00FF
$0100–$013F
.
.
.
$3F80–$3FBF
$3FC0–$3FFF
NOTE
Physical location $0000-$000E is RAM. Physical location $000F is register
X. D[X] register is mapped to address $000E only. The physical RAM in
$000E can be accessing through D[X] register when X register is either $0E
or $CE with PAGESEL is $00.
When PAGESEL register is $00, paging window is mapped to the first page
($00-$3F). Paged location $00C0–$00CE is mapped to physical location
$0000-$000E, i.e., RAM. Paged location $00CF is mapped to register X.
Therefore, accessing address $CE returns the physical RAM content in
$000E, accessing address $000E returns D[X] register content.
MC9RS08KA2 Series Data Sheet, Rev. 4
34
Freescale Semiconductor