HD64F38602R Datasheet, PDF (77/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 3 Exception Handling
RES
Reset cleared
Initial program
Vector fetch Internal ^{instruction prefetch}
processing
φ
Internal
address bus
Internal read
signal
Internal write
signal
Internal data
bus (16 bits)
(1)
(2)
(2)
(3)
(1) Reset exception handling vector address (H'0000)
(2) Program start address
(3) Initial program instruction
Figure 3.1 Reset Exception Handling Sequence
3.2.2 Interrupt Immediately after Reset
Immediately after a reset, if an interrupt is accepted before the stack pointer (SP) is initialized, PC
and CCR will not be pushed onto the stack correctly, resulting in program runaway. To prevent
this, immediately after reset exception handling all interrupts are masked. For this reason, the
initial program instruction is always executed immediately after a reset. This instruction should
initialize the stack pointer (e.g. MOV.L #xx: 32, SP).
Rev. 3.00 May 15, 2007 Page 45 of 516
REJ09B0152-0300