Section 4 Exception Handling
Rev. 2.00 Mar 09, 2006 page 142 of 906
REJ09B0292-0200
4.8
Usage Notes
4.8.1
Value of Stack Pointer (SP)
The value of the stack pointer must always be a multiple of four, otherwise an address error will
occur when the stack is accessed during exception handling.
4.8.2
Value of Vector Base Register (VBR)
The value of the vector base register must always be a multiple of four, otherwise an address error
will occur when the vector table is accessed during exception handling.
4.8.3
Address Errors Caused by Stacking of Address Error Exception Handling
If the stack pointer value is not a multiple of four, an address error will occur during stacking of
the exception handling (interrupts, etc.). Address error exception handling will begin after the
original exception handling ends, but address errors will continue to occur. To ensure that address
error exception handling does not go into an endless loop, no address errors are accepted at that
point. This allows program control to be shifted to the address error exception service routine and
enables error handling to be carried out.
When an address error occurs during exception handling stacking, the stacking bus cycle (write) is
executed. In stacking of the status register (SR) and program counter (PC), the SP is decremented
by 4 for both, so the value of SP will not be a multiple of four after the stacking either. The
address value output during stacking is the SP value, so the address where the error occurred is
itself output. This means that the write data stacked will be undefined.
4.8.4
Manual Reset during Register Access
Do not initiate a manual reset during access of a bus state controller (BSC), user break controller
(UBC), or pin function controller (PFC) register, or the frequency modification register (FMR),
otherwise a write error may result.
Summary of Contents for SH7616
Page 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Page 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Page 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Page 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Page 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Page 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Page 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Page 935: ...SH7616 Hardware Manual ...