HD6473837H Datasheet, PDF (82/562 Pages) Renesas Technology Corp – Hardware Manual

RES
MD0
Reset cleared
Program initial
Vector fetch Internal ^{instruction prefetch}
processing
φ
8,192 clock
cycles
Internal
address bus
(1)
(2)
Internal read
signal
Internal write
signal
Internal data
bus (16-bit)
(2)
(3)
(1) Reset exception handling vector address (H'0000)
(2) Program start address
(3) First instruction of program
Figure 3.2 Reset Sequence (when MD0 Pin is Low)
3.2.3 Interrupt Immediately after Reset
After a reset, if an interrupt were to be accepted before the stack pointer (SP: R7) was initialized,
PC and CCR would 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.W #xx: 16, SP).
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