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Section 18 Power-Down States
Rev.2.00 Jun. 28, 2007 Page 576 of 666
REJ09B0311-0200
18.7.2 Clearing
Software Standby Mode
Software standby mode is cleared by an external interrupt (NMI pin, or pins
IRQ0
to
IRQ11
*), or
by means of the
RES
pin or
STBY
pin.
1. Clearing by interrupt
When an NMI or IRQ0 to IRQ11* interrupt request signal is input, clock oscillation starts, and
after the elapse of the time set in bits STS4 to STS0 in SBYCR, stable clocks are supplied to
the entire LSI, software standby mode is cleared, and interrupt exception handling is started.
When clearing software standby mode with an IRQ0 to IRQ11* interrupt, set the
corresponding enable bit to 1 and ensure that no interrupt with a higher priority than interrupts
IRQ0 to IRQ11* is generated. Software standby mode cannot be cleared if the interrupt has
been masked on the CPU side or has been designated as a DTC activation source.
Note: * By setting the SSIn bit in SSIER to 1,
IRQ0
to
IRQ11
can be used as a software
standby mode clearing source.
2. Clearing by
RES
pin
When the
RES
pin is driven low, clock oscillation is started. At the same time as clock
oscillation starts, clocks are supplied to the entire LSI. Note that the
RES
pin must be held low
until clock oscillation settles. When the
RES
pin goes high, the CPU begins reset exception
handling.
3. Clearing by
STBY
pin
When the
STBY
pin is driven low, a transition is made to hardware standby mode.
18.7.3
Setting Oscillation Settling Time after Clearing Software Standby Mode
Bits STS4 to STS0 in SBYCR should be set as described below.
1. Using a crystal resonator
Set bits STS4 to STS0 so that the standby time is at least equal to the oscillation settling time.
Table 18.2 shows the standby times for operating frequencies and settings of bits STS4 to
STS0.
2. Using an external clock
A PLL circuit settling time is necessary. Refer to table 18.2 to set the standby time.
Summary of Contents for H8SX/1650
Page 2: ...Rev 2 00 Jun 28 2007 Page ii of xxii...
Page 106: ...Section 4 Exception Handling Rev 2 00 Jun 28 2007 Page 84 of 666 REJ09B0311 0200...
Page 142: ...Section 5 Interrupt Controller Rev 2 00 Jun 28 2007 Page 120 of 666 REJ09B0311 0200...
Page 326: ...Section 8 I O Ports Rev 2 00 Jun 28 2007 Page 304 of 666 REJ09B0311 0200...
Page 470: ...Section 12 Watchdog Timer WDT Rev 2 00 Jun 28 2007 Page 448 of 666 REJ09B0311 0200...
Page 566: ...Section 14 A D Converter Rev 2 00 Jun 28 2007 Page 544 of 666 REJ09B0311 0200...
Page 574: ...Section 16 RAM Rev 2 00 Jun 28 2007 Page 552 of 666 REJ09B0311 0200...
Page 584: ...Section 17 Clock Pulse Generator Rev 2 00 Jun 28 2007 Page 562 of 666 REJ09B0311 0200...
Page 638: ...Section 19 List of Registers Rev 2 00 Jun 28 2007 Page 616 of 666 REJ09B0311 0200...
Page 668: ...Section 20 Electrical Characteristics Rev 2 00 Jun 28 2007 Page 646 of 666 REJ09B0311 0200...
Page 676: ...Appendix Rev 2 00 Jun 28 2007 Page 654 of 666 REJ09B0311 0200...
Page 688: ...Rev 2 00 Jun 28 2007 Page 666 of 666 REJ09B0311 0200...
Page 691: ......
Page 692: ...H8SX 1650 Group Hardware Manual...