
CHAPTER 3 CPU ARCHITECTURE
User’s Manual U17854EJ9V0UD
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3.1.4 Special function register (SFR) area
On-chip peripheral hardware special function registers (SFRs) are allocated in the area FFF00H to FFFFFH (see
Table 3-5 in 3.2.4 Special function registers (SFRs)).
Caution
Do not access addresses to which SFRs are not assigned.
3.1.5 Extended special function register (2nd SFR: 2nd Special Function Register) area
On-chip peripheral hardware special function registers (2nd SFRs) are allocated in the area F0000H to F07FFH
(see Table 3-6 in 3.2.5 Extended Special function registers (2nd SFRs: 2nd Special Function Registers)).
SFRs other than those in the SFR area (FFF00H to FFFFFH) are allocated to this area.
An instruction that
accesses the extended SFR area, however, is 1 byte longer than an instruction that accesses the SFR area.
Caution
Do not access addresses to which extended SFR are not assigned.