DSPIC30F2012 Microchip Technology Inc., DSPIC30F2012 Datasheet - Page 68

• Manufacturer Part Number: DSPIC30F2012
• Description: Dspic30f2011/2012/3012/3013 High-performance Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

dsPIC30F2011/2012/3012/3013
Address Error Trap:
This trap is initiated when any of the following
circumstances occurs:
1.
2.
3.
4.
5.
6.
DS70139E-page 66
Note:
A misaligned data word access is attempted.
A data fetch from our unimplemented data
memory location is attempted.
A data access of an unimplemented program
memory location is attempted.
An instruction fetch from vector space is
attempted.
Execution of a “BRA #literal” instruction or a
“GOTO #literal” instruction, where literal
is an unimplemented program memory address.
Executing instructions after modifying the PC to
point to unimplemented program memory
addresses. The PC may be modified by loading
a value into the stack and executing a RETURN
instruction.
In the MAC class of instructions, wherein
the data space is split into X and Y data
space, unimplemented X space includes
all of Y space, and unimplemented Y
space includes all of X space.
Stack Error Trap:
This trap is initiated under the following conditions:
1.
2.
Oscillator Fail Trap:
This trap is initiated if the external oscillator fails and
operation becomes reliant on an internal RC backup.
8.3.2
It is possible that multiple traps can become active
within the same cycle (e.g., a misaligned word stack
write to an overflowed address). In such a case, the
fixed priority shown in Figure 8-2 is implemented,
which may require the user to check if other traps are
pending, in order to completely correct the Fault.
‘Soft’ traps include exceptions of priority level 8 through
level 11, inclusive. The arithmetic error trap (level 11)
falls into this category of traps.
‘Hard’ traps include exceptions of priority level 12
through level 15, inclusive. The address error (level
12), stack error (level 13) and oscillator error (level 14)
traps fall into this category.
Each hard trap that occurs must be acknowledged
before code execution of any type can continue. If a
lower priority hard trap occurs while a higher priority
trap is pending, acknowledged, or is being processed,
a hard trap conflict occurs.
The device is automatically Reset in a hard trap conflict
condition. The TRAPR Status bit (RCON<15>) is set
when the Reset occurs, so that the condition may be
detected in software.
The Stack Pointer is loaded with a value which
is greater than the (user programmable) limit
value written into the SPLIM register (stack
overflow).
The Stack Pointer is loaded with a value which
is less than 0x0800 (simple stack underflow).
HARD AND SOFT TRAPS
© 2006 Microchip Technology Inc.