Section 16 Watchdog Timer and Reset
Rev.1.00 Dec. 13, 2005 Page 625 of 1286
REJ09B0158-0100
Section 16 Watchdog Timer and Reset
The reset and watchdog timer (WDT) control circuit comprises the reset control unit and WDT
control unit which control the power-on reset sequence and a reset for on-chip peripheral modules
and external devices.
The WDT is a one-channel timer which can be used as the watchdog timer or interval timer.
16.1 Features
•
The watchdog timer unit monitors a system crash using a timer counting at specified intervals.
•
The watchdog timer unit generates a reset for on-chip peripheral modules when a WDT
overflow occurs.
•
A power-on reset or a manual reset can be selectable, when a manual reset is selected, the
MRESETOUT
pin is asserted.
•
Generates the interval timer interrupt when counter overflow occurs in interval timer mode.
•
The maximum time until the watchdog timer overflows is approximately 21 seconds (when the
peripheral clock Pck is 50 MHz).
•
Writing to WDT-related registers is not normally allowed. A specified code in the upper bits of
write data enables writing to the registers.
WTCNT and WTCSR differ from other registers in being more difficult to write to. The
procedure for writing to these registers is given below.
Summary of Contents for SH7780 Series
Page 2: ...Rev 1 00 Dec 13 2005 Page ii of l ...
Page 28: ...Rev 1 00 Dec 13 2005 Page xxviii of l ...
Page 50: ...Rev 1 00 Dec 13 2005 Page l of l ...
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 ...
Page 1336: ...Rev 1 00 Dec 13 2005 Page 1286 of 1286 REJ09B0158 0100 ...
Page 1339: ......
Page 1340: ...SH7780 Hardware Manual ...