CHAPTER 3 CPU ARCHITECTURE
User’s Manual U15075EJ2V1UD
53
3.1.2 Internal data memory (internal high-speed RAM) space
The
µ
PD789426, 789436, 789446, and 789456 Subseries products incorporate the following RAM.
(1) Internal high-speed RAM
Internal high-speed RAM is incorporated in the area between FD00H and FEFFH.
The internal high-speed RAM is also used as a stack.
(2) LCD display RAM
LCD display RAM is incorporated.
The LCD display RAM can also be used as ordinary RAM.
Each subseries incorporates LCD display RAM with the following capacity.
Table 3-3. LCD Display RAM Capacity
Subseries Name
Area
Capacity
µ
PD789426, 789436 Subseries
FA00H to FA04H
5
×
4 bits
µ
PD789446, 789456 Subseries
FA00H to FA0EH
15
×
4 bits
3.1.3 Special function register (SFR) area
Special function registers (SFRs) of on-chip peripheral hardware are allocated in the area between FF00H to
FFFFH (see
Table 3-4
).