DS07-16303-3E Datasheet, PDF (20/97 Pages) Fujitsu Component Limited. – 32-bit RISC Microcontroller CMOS FR30 Series

MB91121
s GENERAL-PURPOSE REGISTERS
R0 to R15 are general-purpose registers embedded on the CPU. These registers functions as an accumulator
and a memory access pointer (field for indicating address) .
• Register bank structure
32 bits
Initial value
R0
XXXX XXXXH
R1
R12
R13
AC (Accumulator)
R14
FP (Frame Pointer)
XXXX XXXXH
R15
SP (Stack Pointer)
0 0 0 0 0 0 0 0H
Of the above 16 registers, following registers have special functions. To support the special functions, part of
the instruction set has been sophisticated to have enhanced functions.
R13 : Virtual accumulator (AC)
R14 : Frame pointer (FP)
R15 : Stack pointer (SP)
Upon reset, values in R0 to R14 are not fixed. Value in R15 is initialized to be 0000 0000H (SSP value) .
20