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R01UH0336EJ0102 Rev.1.02
Page 287 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 8 Reset Controller
8.2.3
External RESET
A system reset is performed when a low level signal is applied to the RESET
pin.
SYSRES clears the RESF register to 8000
H
. The RESF.RESF15 bit
represents the external RESET event.
The RESF.RESF15 bit is not automatically cleared. It is cleared by
• setting RESFC.RESFC15 = 1
The RESET signal is passed through an analog noise filter to prevent
erroneous resets due to noise.
The following figure shows the timing when an external reset is performed. It
explains the effect of the noise eliminator.
Figure 8-3
External RESET Timing
The analog delay is caused by the analog filter. The filter regards pulses up to
a certain width as noise and suppresses them.
For the noise-cancelling intervals, see Table 2-51, List of Noise-Cancelling
Intervals and Sampling Clock for Noise Cancellation, and for the minimum
RESET pulse width, see Section 27.6.5, Reset Timing.
SYSRES
Analog
delay
("noise")
Analog
delay
("noise")
RESET
Analog
delay
Analog
delay