Freescale Semiconductor MCF5480 - Manual (Page 208)

MCF548x Reference Manual, Rev. 3
6-18 Freescale Semiconductor
In addition to these vectors, attempting to execute a FRESTORE instruction with a unsupported frame
value generates a format error exception (vector 14). See the FRESTORE instruction in the ColdFire
Programmer’s Reference Manual.
Attempting to execute an FPU instruction with an undefined or unsupported value in the 6-bit effective
address, the 3-bit source/destination specifier, or the 7-bit opmode generates a line-F emulator exception,
vector 11. See Table 6-23 .
6.6.1 Floating-Point Arithmetic Exceptions
This section describes floating-point arithmetic exceptions; Table 6-11 lists these exceptions in order of
priority:
Most floating-point exceptions are taken when the next floating-point arithmetic instruction is encountered
(this is called a pre-instruction exception). Exceptions set during a floating-point store to memory or to an
integer register are taken immediately (post-instruction exception).
Note that FMOVE is considered an arithmetic instruction because the result is rounded. Only FMOVE
with any destination other than a floating-point register (sometimes called FMOVE OUT) can generate
post-instruction exceptions. Post-instruction exceptions never write the destination. After a
post-instruction exception, processing continues with the next instruction.
Table 6-10. Floating-Point Exception Vectors
Vector Number Vector Offset Program Counter Assignment
48 0x0C0 Fault Floating-point branch/set on unordered condition
49 0x0C4 NextFP or Fault Floating-point inexact result
50 0x0C8 NextFP Floating-point divide-by-zero
51 0x0CC NextFP or Fault Floating-point underflow
52 0x0D0 NextFP or Fault Floating-point operand error
53 0x0D4 NextFP or Fault Floating-point overflow
54 0x0D8 NextFP or Fault Floating-point input NAN
55 0x0DC NextFP or Fault Floating-point input denormalized number
Table 6-11. Exception Priorities
Priority Exception
1 Branch/set on unordered (BSUN)
2 Input Not-a-Number (INAN)
3 Input denormalized number (IDE)
4 Operand error (OPERR)
5 Overflow (OVFL)
6 Underflow (UNFL)
7 Divide-by-zero (DZ)
8 Inexact (INEX)