16. Watchdog Timer and Reset (WDT)
Rev.1.00 Jan. 10, 2008 Page 769 of 1658
REJ09B0261-0100
16.4
Operation
16.4.1
Reset Request
Power-on reset and manual reset are available. Their requesting sources are described below.
(1)
Power-On Reset
•
Requesting sources
⎯
A low level input on the
PRESET
pin
⎯
WDTCNT overflow when the WT/
IT
bit is 1 and the RSTS bit is 0 in WDTCSR
⎯
The H-UDI reset (For details, see section 30, User Debugging Interface (H-UDI))
•
Branch address: H'A000 0000
•
Operation until branching
The exception code H'000 is set in EXPEVT. After initializing VBR and SR, the processing
branches by setting PC = H'A000 0000.
During initialization, the VBR register is rest to H'0000 0000. The SR register is initialized
such that the MD, RB, and BL bits are set to 1, the FD bit is cleared to 0, and the interrupt
mask level bits (IMASK3 to IMASK0) are set to B'1111.
Then, the CPU and peripheral modules are initialized. For details, refer to the register
descriptions in the corresponding sections.
At power-on, ensure that a low level is input to the
PRESET
pin. A low level input is also
needed on the
TRST
pin to initialize the H-UDI.
Power_on_reset()
{
EXPEVT = H'0000 0000;
VBR = H'0000 0000;
SR.MD = 1;
SR.RB = 1;
SR.BL = 1;
SR.(I0-I3) = B'1111;
SR.FD = 0;
Initialize_CPU();
Initialize_Module(PowerOn);
PC = H'A000 0000;
}
Summary of Contents for SH7781
Page 4: ...Rev 1 00 Jan 10 2008 Page iv of xxx REJ09B0261 0100 ...
Page 74: ...2 Programming Model Rev 1 00 Jan 10 2008 Page 44 of 1658 REJ09B0261 0100 ...
Page 272: ...8 Caches Rev 1 00 Jan 10 2008 Page 242 of 1658 REJ09B0261 0100 ...
Page 376: ...10 Interrupt Controller INTC Rev 1 00 Jan 10 2008 Page 346 of 1658 REJ09B0261 0100 ...
Page 694: ...13 PCI Controller PCIC Rev 1 00 Jan 10 2008 Page 664 of 1658 REJ09B0261 0100 ...
Page 762: ...14 Direct Memory Access Controller DMAC Rev 1 00 Jan 10 2008 Page 732 of 1658 REJ09B0261 0100 ...
Page 788: ...15 Clock Pulse Generator CPG Rev 1 00 Jan 10 2008 Page 758 of 1658 REJ09B0261 0100 ...
Page 828: ...17 Power Down Mode Rev 1 00 Jan 10 2008 Page 798 of 1658 REJ09B0261 0100 ...
Page 846: ...18 Timer Unit TMU Rev 1 00 Jan 10 2008 Page 816 of 1658 REJ09B0261 0100 ...
Page 1292: ...24 Multimedia Card Interface MMCIF Rev 1 00 Jan 10 2008 Page 1262 of 1658 REJ09B0261 0100 ...
Page 1326: ...25 Audio Codec Interface HAC Rev 1 00 Jan 10 2008 Page 1296 of 1658 REJ09B0261 0100 ...
Page 1482: ...28 General Purpose I O Ports GPIO Rev 1 00 Jan 10 2008 Page 1452 of 1658 REJ09B0261 0100 ...
Page 1538: ...30 User Debugging Interface H UDI Rev 1 00 Jan 10 2008 Page 1508 of 1658 REJ09B0261 0100 ...
Page 1688: ...Appendix Rev 1 00 Jan 10 2008 Page 1658 of 1658 REJ09B0261 0100 ...
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Page 1692: ...SH7785 Hardware Manual ...