H8SLASH300H datasheet(77/552 Pages) RENESAS

部件名	H8/300H

功能描述	Renesas 16-Bit Single-Chip Microcomputer

PDF	552 Pages

Scroll/Zoom	100%

制造商	RENESAS [Renesas Technology Corp]

网页	http://www.renesas.com

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77 / 552 page

Section 3 Exception Handling

Rev. 3.00 May 15, 2007 Page 45 of 516

REJ09B0152-0300

Vector fetch

Internal

address bus

Internal read

signal

Internal write

signal

Internal data

bus (16 bits)

RES

Internal

processing

Initial program

instruction prefetch

(1) Reset exception handling vector address (H'0000)

(2) Program start address

(3) Initial program instruction

(2)

(3)

(2)

(1)

Reset cleared

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).

H8/300H 数据表(PDF) 77 Page - Renesas Technology Corp