CHAPTER 3 CPU ARCHITECTURE
Preliminary User’s Manual U19014EJ1V0UD
35
3.1.2 Internal data memory space
The
µ
PD78F0730 incorporates the following RAMs.
(1) Internal high-speed RAM
Table 3-5. Internal High-Speed RAM Capacity
Part Number
Internal High-Speed RAM
µ
PD78F0730 1,024
×
8 bits (FB00H to FEFFH)
The 32-byte area FEE0H to FEFFH is assigned to four general-purpose register banks consisting of eight 8-bit
registers per bank.
This area 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
Table 3-6. Internal Expansion RAM Capacity
Part Number
Internal Expansion RAM
µ
PD78F0730 2,048
×
8 bits (F000H to F7FFH)
The internal expansion RAM can also be used as a normal data area similar to the internal high-speed RAM, as
well as a program area in which instructions can be written and executed.
The internal expansion RAM cannot be used as a stack memory.
3.1.3 Special function register (SFR) area
On-chip peripheral hardware special function registers (SFRs) are allocated in the area from FF00H to FFFFH (see
Table 3-7 Special Function Register List
in
3.2.3 Special function registers (SFRs)
).
Caution Do not access addresses to which SFRs are not assigned.
3.1.4 USB area
Some registers for USB (UF0DD0 to UF0DD17 and UF0CIE0 to UF0CIE255) are allocated in the area from F9D1H
to FAFFH (see
12.4.3 Request data registers
).
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