MC68EC040RC40A Freescale Semiconductor, MC68EC040RC40A Datasheet - Page 237

• Manufacturer Part Number: MC68EC040RC40A
• Description: IC MPU 32BIT 40MHZ 179-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC040RC40A

• Processor Type: M680x0 32-Bit
• Speed: 40MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 179-PGA
• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant
• Features: -

8.4.6 Access Error Stack Frame (Format $7)
A 30-word access error stack frame is created for data and instruction access faults other
than instruction address errors. In addition to information about the current processor
status and the faulted access, the stack frame also contains pending write-backs that the
access error exception handler must complete. The following paragraphs describe in
detail the format for this frame and how the processor uses it when returning from
exception processing.
8.4.6.1 EFFECTIVE ADDRESS. The effective address contains address information when
one of the continuation flags CM, CT, CU, or CP in the SSW is set.
8.4.6.2 SPECIAL STATUS WORD (SSW). The SSW information indicates whether an
access to the instruction stream or the data stream (or both) caused the fault and contains
status information for the faulted access. Figure 8-7 illustrates the SSW format.
8-24
CP
15
SP
+$02
+$06
+$08
+$0A
+$0C
+$0E
+$10
+$12
+$14
+$18
+$1C
+$20
+$24
+$28
+$2C
+$30
+$34
+$38
CU
14
WRITE-BACK 1 DATA/PUSH DATA LW0 (WB1D/PD0)
15
0 1 1 1
$00
$00
$00
WRITE-BACK 3 ADDRESS (WB3A)
WRITE-BACK 2 ADDRESS (WB2A)
WRITE-BACK 1 ADDRESS (WB1A)
13
CT
ACCESS ERROR STACK FRAME
SPECIAL STATUS WORD (SSW)
WRITE-BACK 3 DATA (WB3D)
WRITE-BACK 2 DATA (WB2D)
Stack Frames
EFFECTIVE ADDRESS (EA)
PUSH DATA LW 1 (PD1)
PUSH DATA LW 2 (PD2)
PUSH DATA LW 3 (PD3)
(30 WORDS)–FORMAT $7
FAULT ADDRESS (FA)
PROGRAM COUNTER
STATUS REGISTER
CM
12
WRITE-BACK 3 STATUS (WB3S)
WRITE-BACK 2 STATUS (WB2S)
WRITE-BACK 1 STATUS (WB1S)
VECTOR OFFSET
Figure 8-7. Special Status Word Format
MA
11
Freescale Semiconductor, Inc.
For More Information On This Product,
ATC
10
M68040 USER’S MANUAL
Go to: www.freescale.com
LK
9
0
RW
• Data or Instruction Access
8
Fault (ATC Fault or Bus
Error)
Exception Types
7
X
6
SIZE
5
4
• Next Instruction
TT
Stacked PC Points To
3
2
MOTOROLA
TM
1
0