Section 4 Clock Pulse Generator (CPG)
Rev. 3.00 Sep. 27, 2007 Page 68 of 758
REJ09B0243-0300
4.7
Function for Detecting Oscillator Stop
This CPG detects a stop in the clock input if any system abnormality halts the clock supply.
When no change has been detected in the EXTAL input for a certain period, the OSCSTOP bit in
OSCCR is set to 1 and this state is retained until a power-on reset is input through the
RES
pin or
software standby mode is canceled. If the OSCERS bit is set to 1 at this time, an oscillation stop
detection flag signal is output through the
WDTOVF
pin. In addition, the high-current ports (pins
to which the TIOC3B, TIOC3D, and TIOC4A to TIOC4D signals in the MTU2 are assigned) are
always placed in high-impedance state regardless of the PFC setting. For details, refer to appendix
A, Pin States.
Even in software standby mode, these pins are always placed in high-impedance state. For details,
refer to appendix A, Pin States. These pins enter the normal state after software standby mode is
canceled. Under an abnormal condition where oscillation stops while the LSI is not in software
standby mode, LSI operations other than the oscillation stop detection function become
unpredictable. In this case, even after oscillation is restarted, LSI operations including the above
high-current pins become unpredictable.
Even while no change is detected in the EXTAL input, the PLL circuit in this LSI continues
oscillating at a frequency range from 100 kHz to 10 MHz (depending on the temperature and
operating voltage).
Summary of Contents for SH7124 R5F7124
Page 2: ...Rev 3 00 Sep 27 2007 Page ii of xx ...
Page 8: ...Rev 3 00 Sep 27 2007 Page viii of xx ...
Page 36: ...Section 1 Overview Rev 3 00 Sep 27 2007 Page 16 of 758 REJ09B0243 0300 ...
Page 68: ...Section 2 CPU Rev 3 00 Sep 27 2007 Page 48 of 758 REJ09B0243 0300 ...
Page 108: ...Section 5 Exception Handling Rev 3 00 Sep 27 2007 Page 88 of 758 REJ09B0243 0300 ...
Page 166: ...Section 7 User Break Controller UBC Rev 3 00 Sep 27 2007 Page 146 of 758 REJ09B0243 0300 ...
Page 724: ...Section 20 List of Registers Rev 3 00 Sep 27 2007 Page 704 of 758 REJ09B0243 0300 ...
Page 772: ...Rev 3 00 Sep 27 2007 Page 752 of 758 REJ09B0243 0300 ...
Page 778: ...Rev 3 00 Sep 27 2007 Page 758 of 758 REJ09B0243 0300 ...
Page 781: ......