SH7751 Datasheet, PDF (246/1224 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

5. Exceptions
(2) Manual Reset
• Sources:
⎯ MRESET pin low level and RESET pin high level
⎯ When a general exception other than a user break occurs while the BL bit is set to 1 in SR
⎯ When the watchdog timer overflows while the RSTS bit is set to 1 in WTCSR. For details,
see section 10, Clock Oscillation Circuits.
• Transition address: H'A000 0000
• Transition operations:
Exception code H'020 is set in EXPEVT, initialization of VBR and SR is performed, and a
branch is made to PC = H'A000 0000.
In the initialization processing, the VBR register is set to H'0000 0000, and in SR, the MD,
RB, and BL bits are set to 1, the FD bit is cleared to 0, and the interrupt mask bits (IMASK)
are set to B'1111.
CPU and on-chip peripheral module initialization is performed. For details, see the register
descriptions in the relevant sections.
Manual_reset()
{
EXPEVT = H'00000020;
VBR = H'00000000;
SR.MD = 1;
SR.RB = 1;
SR.BL = 1;
SR.IMASK = B'1111;
SR.FD = 0;
Initialize_CPU();
Initialize_Module(Manual);
PC = H'A0000000;
}
Table 5.3 Types of Reset
Type
Power-on reset
Manual reset
Reset State Transition
Conditions
MRESET
RESET
—
Low
Low
High
Internal States
CPU
On-Chip Peripheral Modules
Initialized
Initialized
See Register Configuration in
each section
Rev.4.00 Oct. 10, 2008 Page 148 of 1122
REJ09B0370-0400