H8SSLASH2214 datasheet(145/936 Pages) RENESAS

145 / 936 page

Section 4 Exception Handling

Rev.4.00 Sep. 18, 2008 Page 85 of 872

REJ09B0189-0400

Address bus

Vector fetch

Internal

processing

Prefetch of first

program instruction

(1) (3) Reset exception handling vector address (for a power-on reset, (1) = H'000000,

(3) = H'000002; for a manual reset, (1) = H'000004, (3) = H'000006)

(2) (4) Start address (contents of reset exception handling vector address)

(5)

Start address ((5) = (2) (4))

(6)

First program instruction

RES, MRES

(1)

(5)

High

(2)

(4)

(3)

(6)

HWR, LWR

D15 to D0

Note: * Three program wait states are inserted.

Figure 4.3 Reset Sequence (Mode 4)

4.2.4

Interrupts after Reset

If an interrupt is accepted after a reset but before the stack pointer (SP) is initialized, the PC and

CCR will not be saved correctly, leading to a program crash. To prevent this, all interrupt requests,

including NMI, are disabled immediately after a reset. Since the first instruction of a program is

always executed immediately after the reset state ends, make sure that this instruction initializes

the stack pointer (example: MOV.L #xx:32, SP).

4.2.5

State of On-Chip Supporting Modules after Reset Release

After reset release, MSTPCRA is initialized to H'3F, MSTPCRB and MSTPCRC are initialized to

H'FF, and all modules except the DMAC and DTC enter module stop mode. Consequently, on-

chip supporting module registers cannot be read or written to. Register reading and writing is

enabled when module stop mode is exited.

H8S/2214 Scheda tecnica(PDF) 145 Page - Renesas Technology Corp