Section 16 Watchdog Timer and Reset
Rev.1.00 Dec. 13, 2005 Page 636 of 1286
REJ09B0158-0100
And the time until WDTCNT overflows becomes the minimum value when H'001 is set to
WDTST. The minimum overflow time is approximately 5.243 ms (= 2^1 [bit]
×
5.243 [ms]).
16.4.5
Clearing WDT Counter
Writing H'55 to WDTBST with longword access clears WDTBCNT and writing the overflow
setting value to WDTST clears WDTCNT.
16.5
Status Pin Change Timing during Reset
16.5.1
Power-On Reset by PRESET
A power-on reset is to initialize the on-chip PLL circuit when this LSI goes to the power-on reset
state by the
PERSET
pin low level input and then it is necessary to ensure the synchronization
settling time of the PLL circuit. Therefore, do not input high level to the
PRESET
pin during the
synchronization settling time of the PLL. The PLL synchronization settling time is the total value
of the PLL1 synchronization settling time and the PLL2 synchronization settling time.
After the
PRESET
pin input level is changed from low level to high level, the reset state is
continued during the reset holding time in the LSI. The reset holding time is 20 clock cycles of the
XTAL clock and thereafter equal to or more than 45 clock cycles of the peripheral clock (Pck).
The STATUS [1:0] pins output timing that indicates the reset state is asynchronous, and that
indicates a normal operation is synchronous with the peripheral clock (Pck) and asynchronous
with both the XTAL clock and the CLKOUT pin output clock.
Turning On Power Supply
When turning on the power supply, the
PRESET
pin input level should be low level. And the
TRST
pin input level should be low level to initialize the H-UDI.
Summary of Contents for SH7780 Series
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Page 82: ...Section 1 Overview Rev 1 00 Dec 13 2005 Page 32 of 1286 REJ09B0158 0100 ...
Page 122: ...Section 3 Instruction Set Rev 1 00 Dec 13 2005 Page 72 of 1286 REJ09B0158 0100 ...
Page 146: ...Section 4 Pipelining Rev 1 00 Dec 13 2005 Page 96 of 1286 REJ09B0158 0100 ...
Page 196: ...Section 6 Floating Point Unit FPU Rev 1 00 Dec 13 2005 Page 146 of 1286 REJ09B0158 0100 ...
Page 292: ...Section 9 L Memory Rev 1 00 Dec 13 2005 Page 242 of 1286 REJ09B0158 0100 ...
Page 492: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Dec 13 2005 Page 442 of 1286 REJ09B0158 0100 ...
Page 674: ...Section 15 Clock Pulse Generator CPG Rev 1 00 Dec 13 2005 Page 624 of 1286 REJ09B0158 0100 ...
Page 692: ...Section 16 Watchdog Timer and Reset Rev 1 00 Dec 13 2005 Page 642 of 1286 REJ09B0158 0100 ...
Page 726: ...Section 18 Timer Unit TMU Rev 1 00 Dec 13 2005 Page 676 of 1286 REJ09B0158 0100 ...
Page 1032: ...Section 25 Audio Codec Interface HAC Rev 1 00 Dec 13 2005 Page 982 of 1286 REJ09B0158 0100 ...
Page 1150: ...Section 28 General Purpose I O GPIO Rev 1 00 Dec 13 2005 Page 1100 of 1286 REJ09B0158 0100 ...
Page 1184: ...Section 29 User Break Controller UBC Rev 1 00 Dec 13 2005 Page 1134 of 1286 REJ09B0158 0100 ...
Page 1266: ...Section 31 Electrical Characteristics Rev 1 00 Dec 13 2005 Page 1216 of 1286 REJ09B0158 0100 ...
Page 1328: ...Appendix Rev 1 00 Dec 13 2005 Page 1278 of 1286 REJ09B0158 0100 ...
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