What is the number of instruction cycles for EastLoop block? I have the following code:
#include
__config (_INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF)
cblock 0x20
Delay1
Delay2
Delay3
endc
org 0
Start:
bsf STATUS,RP0
clrf TRISIO
bcf STATUS,RP0
clrf Delay1
clrf Delay2
clrf Delay3
movlw 0xD0
movwf B'100000'
movlw .7
movwf CMCON
MainLoop:
bsf GPIO,GP1
bsf 0x21,5
EastLoop:
nop
decfsz Delay1,f
goto EastLoop
decfsz Delay2,f
goto EastLoop
movwf Delay3
bcf 0x05,1
bsf 0x05,4
decf Delay3,0
bsf 0x20,7
bsf 0x20,3
bsf O'40',1
comf .32,1
NordLoop:
decfsz Delay1,f
goto NordLoop
btfsc GPIO,GP1
goto SetStep
bsf GPIO,GP1
goto SetSStep
SetStep:
bcf GPIO,GP1
SetSStep:
decfsz Delay3,f
goto NordLoop
bcf 0x05,1
bcf 0x05,4
end
Could someone please explain this?
CodePudding user response：
The processor executes assembly instructions in different instruction cycles (according to the complexity of the instruction). You can learn about instruction cycles by reading the datasheet. The total number of instruction cycles is the sum of all instruction cycles according to the program logic. According to the datasheet, the instruction cycles of some of the commands above are as follows:
| Mnemonic | Cycles |
|---|---|
| NOP | 1 |
| DECFSZ | 1 (2) * |
| GOTO | 2 |
| MOVWF | 1 |
| BCF | 1 |
| BSF | 1 |
| DECF | 1 |
| COMF | 1 |
(*) DECFSZ → If the result is 0, then a NOP is executed instead, making it a 2 TCY instruction.
Related Links
CodePudding user response：
I guess you are working with MPLABx. In this case you could count the number of instruction cycles with the stopwatch of the simulator:
- put the PC at the top of
Eastloop - start the stopwatch and reset it to zero
- step thru the loop and the cycles will be count