Renesas SuperH SH-4A - Description of Exceptions; Resets

Rev. 1.50, 10/04, page 75 of 448
5.6 Description of Exceptions
The various exception handling operations explained here are exception sources, transition address
on the occurrence of exception, and processor operation when a transition is made.
5.6.1 Resets
Power-On Reset:
• Condition:
Power-on reset request
• Operations:
Exception code H'000 is set in EXPEVT, initialization of the CPU and on-chip peripheral
module is carried out, and then a branch is made to the reset vector (H'A0000000). For details,
see the register descriptions in the relevant sections. A power-on reset should be executed
when power is supplied.
Manual Reset:
• Condition:
Manual reset request
• Operations:
Exception code H'020 is set in EXPEVT, initialization of the CPU and on-chip peripheral
module is carried out, and then a branch is made to the branch vector (H'A0000000). The
registers initialized by a power-on reset and manual reset are different. For details, see the
register descriptions in the relevant sections.
H-UDI Reset:
• Source: SDIR.TI[7:4] = B'0110 (negation) or B'0111 (assertion)
• Transition address: H'A0000000
• Transition operations:
Exception code H'000 is set in EXPEVT, initialization of VBR and SR is performed, and a
branch is made to PC = H'A0000000.
CPU and on-chip peripheral module initialization is performed. For details, see the register
descriptions in the relevant sections of the hardware manual of the target product.