Freescale Semiconductor MCF51QE128RM manual 2.2 S08 and ColdFire Exception Processing Comparison

Models: MCF51QE128RM

1 424
Download 424 pages 63.71 Kb
Page 157
Image 157

ColdFire Core

Table 7-7. Format Field Encodings

 

 

 

Original SSP @ Time

SSP @ 1st

 

Instruction of

Format Field

of Exception, Bits 1:0

Handler

 

 

 

 

 

 

00

Original SSP - 8

0100

 

 

 

01

Original SSP - 9

0101

 

 

 

10

Original SSP - 10

0110

 

 

 

11

Original SSP - 11

0111

 

 

 

There is a 4-bit fault status field, FS[3:0], at the top of the system stack. This field is defined for access and address errors only and written as zeros for all other exceptions. See Table 7-8.

 

Table 7-8. Fault Status Encodings

 

 

FS[3:0]

Definition

 

 

00xx

Reserved

 

 

0100

Error on instruction fetch

 

 

0101

Reserved

 

 

011x

Reserved

 

 

1000

Error on operand write

 

 

1001

Attempted write to write-protected space

 

 

101x

Reserved

 

 

1100

Error on operand read

 

 

1101

Reserved

 

 

111x

Reserved

 

 

The 8-bit vector number, vector[7:0], defines the exception type and is calculated by the processor for all internal faults and represents the value supplied by the interrupt controller in case of an interrupt. See Table 7-6.

7.3.2.2S08 and ColdFire Exception Processing Comparison

This section presents a brief summary comparing the exception processing differences between the S08 and V1 ColdFire processor families.

MCF51QE128 MCU Series Reference Manual, Rev. 3

Freescale Semiconductor

157

Page 157
Image 157
Freescale Semiconductor MCF51QE128RM manual 2.2 S08 and ColdFire Exception Processing Comparison, Format Field Encodings