MB90560 Datasheet, PDF (94/581 Pages) Fujitsu Component Limited. – 16-BIT MICROCONTROLLER

3.2 Reset Causes and Oscillation Stabilization Wait Intervals
The F²MC-16LX has five reset causes. The oscillation stabilization wait interval for a
reset depends on the reset cause.
s Reset causes and oscillation stabilization wait intervals
Tables 3.2-1 and 3.2-2 summarize reset causes and oscillation stabilization wait intervals.
Table 3.2-1 Reset causes and oscillation stabilization wait intervals
Reset cause
Power-on reset
Watchdog timer
External reset via the RSTX pin
Software reset
Oscillation stabilization wait interval
The corresponding time interval for an oscillation clock
frequency of 4 MHz is given in parentheses.
2¹⁷/HCLK (32.768 ms)
2¹⁷/HCLK (32.768 ms)
None
None
HCLK:Oscillation clock frequency, source oscillation
Table 3.2-2 Oscillation stabilization wait intervals set by the clock selection register
(CKSCR)
WS1
0
0
1
1
WS0
0
1
0
1
Oscillation stabilization wait interval
The corresponding time interval for an oscillation clock frequency of 4 MHz is
given in parentheses.
No oscillation stabilization time.
2¹³/HCLK (2.048 ms)
2¹⁵/HCLK (8.192 ms)
2¹⁷/HCLK (32.768 ms)
HCLK: Oscillation clock frequency
<Check>
Ceramic and crystal oscillators generally require an oscillation stabilization wait interval of
several milliseconds to 10 to 20 milliseconds until they stabilize at their natural frequency. Be
sure to set a proper oscillation stabilization wait interval for the particular oscillator used.
See Chapter 4, "Clocks," for details.
s Oscillation stabilization wait and reset state
A reset operation in response to a power-on reset and other externally activated resets during
stop mode is performed after the oscillation stabilization wait interval has elapsed. This time
interval is generated by the timebase timer. If the external reset has not been released after the
interval, the reset operation is performed after the external reset is released.
70 CHAPTER 3 RESETS
MB90560 series