ColdFire CoreMCF5253 Reference Manual, Rev. 13-8 Freescale Semiconductor3.4 Exception Stack Frame DefinitionThe exception stack frame is shown in Figure 3-6. The first longword of the exception stack frame containsthe 16-bit format/vector word (F/V) and the 16-bit status register, and the second longword contains the32-bit program counter address.Figure 3-6. Exception Stack Frame FormThe 16-bit format/vector word contains 3 unique fields:• A 4-bit format field at the top of the system stack is always written with a value of {4,5,6,7} by theprocessor indicating a two-longword frame format. See Table 3-6.11 $02C Fault Unimplemented line-f opcode12 $030 Next Debug interrupt13 $034 – Reserved14 $038 Fault Format error15 $03C Next Uninitialized interrupt16-23 $040-$05C – Reserved24 $060 Next Spurious interrupt25–31 $064-$07C Next Level 1–7 autovectored interrupts32–47 $080-$0BC Next Trap # 0–15 instructions48–63 $0C0-$0FC – Reserved64–255 $100-$3FC Next User-defined interrupts1 “Fault” refers to the PC of the instruction that caused the exception.2 “Next” refers to the PC of the next instruction that follows the instruction that caused the fault.Table 3-6. Format Field EncodingOriginal A7 @ Time ofException, Bits 1:0A7 @ 1st Instructionof Handler Format Field00 Original A7 - 8 401 Original A7 - 9 510 Original A7 - 10 611 Original A7 - 11 7Table 3-5. Exception Vector Assignments (continued)VectorNumbers(s)VectorOffset (HEX)Stacked 1, 2ProgramCounterAssignmentFORMAT FS[3:0] VECTOR[7:0] FS[1:0]PROGRAM COUNTER[31:0]A7+$04STATUSREGISTER31 27 25 17 15 C
