R01UH0822EJ0100 Rev.1.00
Page 45 of 1041
Jul 31, 2019
RX13T Group
2. CPU
2.2
Register Set of the CPU
The RX CPU has 16 general-purpose registers, nine control registers, and one accumulator used for DSP instructions.
Figure 2.1
Register Set of the CPU
Note 1. The stack pointer (SP) can be the interrupt stack pointer (ISP) or user stack pointer (USP), according to
the value of the U bit in the PSW register.
USP
(User stack pointer)
ISP
(Interrupt stack pointer)
INTB
(Interrupt table register)
PC
(Program counter)
PSW
(Processor status word)
BPC
(Backup PC)
BPSW
(Backup PSW)
FINTV
(Fast interrupt vector register)
R15
R14
R13
R12
R11
R10
R9
R8
R7
R6
R5
R4
R3
R2
R1
R0 (SP)
*1
General-purpose registers
Control registers
b31
b0
b31
b0
DSP instruction register
b63
b0
ACC (Accumulator)
FPSW
(Floating-point status word)