SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 30

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

1) Using only One Datapointer (Code for an 8051)
Initialization Routine
Action
Initialize shadow_variables with source_pointer
Initialize shadow_variables with
destination_pointer
Table Look-up Routine under Real Time Conditions
Action
Save old datapointer
Load Source Pointer
Increment and check for end of table
(execution time not relevant for this
consideration)
Fetch source data byte from ROM table
Save source_pointer and load
destination_pointer
Increment destination_pointer (ex. time not
relevant)
Transfer byte to destination address
Save destination_pointer
Restore old datapointer
Total execution time (machine cycles)
Semiconductor Group
MOVC A,@DPTR
MOVX @DPTR, A
MOV LOW(DES_PTR), DPL
Code
PUSH DPL
PUSH DPH
MOV DPL, LOW(SRC_PTR)
MOV DPH, HIGH(SRC_PTR)
INC DPTR
CJNE…
…
MOV LOW(SRC_PTR), DPL
MOV HIGH(SRC_PTR), DPH
MOV DPL, LOW(DES_PTR)
MOV DPH, HIGH(DES_PTR)
INC DPTR
MOV HIGH(DES_PTR),DPH
POP DPH
POP DPL
–
31
Code
MOV LOW(SRC_PTR), #0FFH
MOV HIGH(SRC_PTR), #1FH
MOV LOW(DES_PTR), #0A0H
MOV HIGH(DES_PTR), #2FH
External Bus Interface
Machine
Cycles
2
2
2
2
–
–
–
2
2
2
2
2
–
2
2
2
2
2
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