DS80C320-ECD DALLAS [Dallas Semiconductor], DS80C320-ECD Datasheet - Page 157
DS80C320-ECD
Manufacturer Part Number
DS80C320-ECD
Description
High-Speed Microcontroller User Guide
Manufacturer
DALLAS [Dallas Semiconductor]
Datasheet
1.DS80C320-ECD.pdf
(175 pages)
- Current page: 157 of 175
- Download datasheet (2Mb)
EXAMPLE: A TRANSIENT CAUSES THE WATCHDOG TO BE DISABLED
C2D2
C2D5
C2D7
C2D9
C2DA
C2DB
C2DC
C2DD
A transient occurs while the opcode is being fetched for the first instruction. The transient causes one bit
of the opcode in the first instruction to be read as a 0 instead of 1. The resulting program is what the
microcontroller would actually execute:
C2D2 80 0A 00
C2D5 79 FF
C2D7 78 90
C2D9 E0
C2DA F6
C2DB 06
C2DC A3
C2DD D9 C2 D9
The resulting jump is to address C2DE. This is not even a real opcode, but would be treated as such. The
resulting fetch is the value C2 D9. This is the opcode for CLR D9h. The bit addressable location D9h
corresponds to the EWT - Enable Watchdog Timer. If the Timed Access procedure did not prevent it,
this errant instruction would disable the Watchdog. Note that now, the program execution is completely
lost. Real opcodes are being replaced by operands, data and garbage. In the High-Speed Microcontroller,
the Watchdog will recover from this state as soon as it times out since it could not have been disabled in
this way.
In the High-Speed Microcontroller it is very hard to contrive a situation that will accidentally disable the
Watchdog. Note, the Timed Access prevents accidentally writing a bit. It can not prevent accidentally
calling the correct code that writes a bit. This is much more unlikely however.
TABLE_READ:
TABLE_READ:
90 0A 00
79 FF
78 90
E0
F6
06
A3
D9 C2 D9
MOV
MOV
MOV
LOOP:
MOVX
MOV
INC
INC
DJNZ
SJMP
MOV
MOV
LOOP:
MOVX
MOV
INC
INC
DJNZ
DPTR, 0A00H
R1, #0FFH
R0, #90H
A, @DPTR
@R0, A
R0
DPTR
R1, LOOP
0BH
R1, #0FFH
R0, #90H
A, @DPTR
@R0, A
R0
DPTR
R1, LOOP
157 of 175
;RELATIVE JUMP BY 10 LOCATIONS
;LOAD COUNTER
;DESTINATION POINTER
;READ DATA BYTE
;STORE IT IN RAM
;NEXT TABLE LOCATION
;NEXT DATA VALUE
;NEXT BYTE OR DONE ?
;LOAD TABLE POINTER
;LOAD COUNTER
;DESTINATION POINTER
;READ DATA BYTE
;STORE IT IN RAM
;NEXT TABLE LOCATION
;NEXT DATA VALUE
;NEXT BYTE OR DONE ?
High-Speed Microcontroller User’s Guide
Related parts for DS80C320-ECD
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
Microcontroller, 8051 Comp., 4 8-Bit I/O Ports, 64K ROM/RAM, 25 MHz, 5 V, PLCC44
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
Microcontroller, 8051 Comp., 4 8-Bit I/O Ports, 64K ROM/RAM, 25 MHz, 5 V, PDIP40
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
High Resolution Temperature Measurement with Dallas Direct-to-Digital Temperature Sensors
Manufacturer:
Dallas Semiconductor
Part Number:
Description:
32.768kHz Temperature-Compensated Crystal Oscillator
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
3.3 volt micromonitor, tolerance 20%
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
Ultra3 LVD/SE SCSI Terminator
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
SCSI Terminator
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet:
Part Number:
Description:
5-Tap Silicon Delay Line
Manufacturer:
Dallas Semiconductor
Datasheet: