upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 397

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

15.1 General
are reset to their initial settings. In addition, oscillation of the main clock is stopped during the reset period, although
oscillation of the subclock continues.
resumes program execution.
necessary.
15.2 Pin Operations
AV
pin of ports 3 to 6 and 9 to 11. If such a resistor is not attached, these pins will be set to high impedance, which could
damage the data in memory devices. Likewise, make sure the pins are handled so as to prevent a similar effect at the
signal outputs of on-chip peripheral I/O functions and output ports.
When a low level is input to the RESET pin, a system reset is performed and the various on-chip hardware devices
When the input at the RESET pin changes from low level to high level, the reset status is released and the CPU
An on-chip noise eliminator uses analog delay to prevent noise-related malfunction at the RESET pin.
During the system reset period, almost all pins are set to high impedance (all pins except for RESET, X2, XT2,
REF
Accordingly, if connected to an external memory device, be sure to attach a pull-up (or pull-down) resistor to each
, V
DD
, V
Internal system
reset signal
SS
, AV
RESET
DD
, AV
X1
SS
Eliminated as noise
, BV
Analog delay
The contents of the various registers should be initialized within the program as
DD
, BV
CHAPTER 15 RESET FUNCTION
SS
Figure 15-1. System Reset Timing
, and IC/V
User’s Manual U12768EJ4V1UD
Analog
delay
Reset is acknowledged
PP
).
Hi-Z
Analog delay
26.2 ms (@ 20 MHz operation)
Oscillation stabilization time
Reset is released
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