Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 72 of 1823
Jul 31, 2019
RX23W Group 2. CPU
2.2.2.1 Interrupt Stack Pointer (ISP)/User Stack Pointer (USP)
The stack pointer (SP) can be either of two types, the interrupt stack pointer (ISP) or the user stack pointer (USP).
Whether the stack pointer operates as the ISP or USP depends on the value of the stack pointer select bit (U) in the
processor status word (PSW).
Set the ISP or USP to a multiple of 4 to reduce the number of cycles required to execute interrupt sequences and
instructions entailing stack manipulation.
2.2.2.2 Exception Table Register (EXTB)
The exception table register (EXTB) specifies the address where the exception vector table starts.
Set the EXTB to a multiple of 4 to reduce the number of cycles required to execute interrupt sequences and instructions
entailing stack manipulation.
2.2.2.3 Interrupt Table Register (INTB)
The interrupt table register (INTB) specifies the address where the interrupt vector table starts.
Set the INTB to a multiple of 4 to reduce the number of cycles required to execute interrupt sequences and instructions
entailing stack manipulation.
2.2.2.4 Program Counter (PC)
The program counter (PC) indicates the address of the instruction being executed.
b31 b0
ISP
Value after reset:
00000000000000000000000000000000
b31 b0
USP
Value after reset:
00000000000000000000000000000000
b31 b0
Value after reset:
11111111111111111111111110000000
b31 b0
Value after reset:
Undefined
b31 b0
Value after reset:
Contents of addresses FFFFFFFCh to FFFFFFFFh

Renesas RX Series Specifications

General

Brand	Renesas
Model	RX Series
Category	Microcontrollers
Language	English