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CHAPTER 3 CPU ARCHITECTURE
User’s Manual U15798EJ2V0UD
3.1.2 Internal data memory space
The
µ
PD780344, 780354, 780344Y, and 780354Y Subseries products incorporate the following RAM.
(1) Internal high-speed RAM
The internal high-speed RAM is assigned to the area FD00H to FEFFH (512 bytes) of the mask ROM version
and to the area FB00H to FEFFH (1,024 bytes) of the flash memory version.
The 32-byte area FEE0H to FEFFH is assigned to four general-purpose register banks configured of eight 8-
bit registers as one bank.
The internal high-speed RAM cannot be used as a program area in which instructions are written and executed.
The internal high-speed RAM can also be used as a stack memory.
(2) Internal expansion RAM
The area F600H to F7FFH (512 bytes) is assigned to the internal expansion RAM.
The internal expansion RAM can be used as a normal data area in the same way as the internal high-speed RAM,
and can be used as a program area in which instructions are written and executed.
(3) LCD display RAM
The area FA00H to FA27H (40 bytes) is assigned to the LCD display RAM.
LCD display RAM can also be used as normal RAM. Therefore, the area not used as LCD display data can be
used as normal RAM.
3.1.3 Special function register (SFR) area
An on-chip peripheral hardware special function register (SFR) is allocated in the area FF00H to FFFFH (refer to
3.2.3 Special function register (SFR) Table 3-3 Special Function Register List
).
Caution Do not access addresses where SFRs are not assigned.
Содержание mPD780344 Series
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