mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 96

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Exception Processing Overview
2.8.1 Exception Stack Frame Definition
The exception stack frame is shown in Figure 2-10. The first longword of the exception
stack frame contains the 16-bit format/vector word (F/V) and the 16-bit status register. The
second longword contains the 32-bit program counter address.
The 16-bit format/vector word contains three unique fields:
2-28
+ 0x04
A7!
• Format field—This 4-bit field at the top of the system stack is always written with a
• Fault status field—The 4-bit field, FS[3–0], at the top of the system stack is defined
value of {4,5,6,7} by the processor indicating a 2-longword frame format. See
Table 2-19. This field records any longword misalignment of the stack pointer that
may have existed when the exception occurred.
for access and address errors along with interrupted debug service routines. See
Table 2-20.
31
0101–011x
1101–111x
0000-001x
FS[3–0]
Format
0100
1000
1001
1100
101x
Original A7 at Time of
Exception, Bits 1–0
28
Figure 2-10. Exception Stack Frame Form
Reserved
Error on instruction fetch
Reserved
Error on operand write
Attempted write to write-protected space
Reserved
Error on operand read
Reserved
00
01
10
11
27
FS[3–2]
Table 2-20. Fault Status Encodings
Table 2-19. Format Field Encoding
26
25
Vector[7–0]
MCF5272 User’s Manual
Program Counter [31–0]
A7 at First Instruction of
18
Original A[7–10]
Original A[7–11]
Original A[7–8]
Original A[7–9]
17
FS[1–0]
Handler
Definition
16
15
Format Field Bits
Status Register
31–28
0100
0101
0110
0111
MOTOROLA
0