HD6412350 Hitachi, HD6412350 Datasheet - Page 103

• Manufacturer Part Number: HD6412350
• Description: (HD6412350 / HD6432351) 16-BIT MICROCONTROLLER
• Manufacturer: Hitachi

4.2.3
The H8S/2350 Series enters the reset state when the RES pin goes low.
To ensure that the H8S/2350 Series is reset, hold the RES pin low for at least 20 ms at power-up.
To reset the H8S/2350 Series during operation, hold the RES pin low for at least 20 states.
When the RES pin goes high after being held low for the necessary time, the H8S/2350 Series
starts reset exception handling as follows:
1. The internal state of the CPU and the registers of the on-chip supporting modules are
2. The reset exception handling vector address is read and transferred to the PC, and program
Figures 4-2 and 4-3 show examples of the reset sequence.
initialized, the T bit is cleared to 0 in EXR, and the I bit is set to 1 in EXR and CCR.
execution starts from the address indicated by the PC.
RES
Internal
address bus
Internal read
signal
Internal write
signal
Internal data
bus
Reset Sequence
ø
(1) Reset exception handling vector address ((1) = H'0000)
(2) Start address (contents of reset exception handling vector address)
(3) Start address ((3) = (2))
(4) First program instruction
Figure 4-2 Reset Sequence (Modes 2 and 3)
Vector
fetch
(1)
(2)
Internal
processing
High
Prefetch of first program
instruction
(3)
(4)
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