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boss

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Joined: 19/08/2011
Location: Canada
Posts: 268

Posted: 04:59pm 23 Mar 2012

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Can someone advise me why "COPY" command is so slow? In this case program is very short, but copy time takes incredible 25 sec.

boss

09:31:04 B:\>timer=0:COPY "595B.BAS" TO "595C.BCK":? timer
25520
09:32:36 B:\>

'=========================================================== ==================
'MAXIMITE BASIC v.3.1 18.3.2012
'AUTHOR: JA
'DEMONSTRACNI PROGRAM POUZITI Shift registru 74HC595 PRO RIZENI 7-SEGMENT LED
' MULTIPLEXOVANEHO DISPLEJE, 500 REFRESH/SEC
'====== DEFINICE POUZITI PINU ================================================
LWRITE=14
SCLK=15
SDATA=16
SPIREAD=10 'Funkce SPI nejen posila data, ale take je cte, takze definice RX
'====== NASTAVENI POCATECNI LOG UROVNE PINU===================================
Pin(LWRITE)=0
Pin(SCLK)=0
Pin(SDATA)=0
Pin(SPIREAD)=1
'======= NASTAVENI FUNKCE PINU 2-VSTUP,8-VYSTUP ==============================
SetPin LWRITE,8
SetPin SCLK,8
SetPin SDATA,8
SetPin SPIREAD,2
'======== DEKLARACE POLI =====================================================
Dim CAS(4)
Dim ZNAK(16)
Dim ZNAKN(16)
'======== PLNENI POLI DATY ===================================================
For I=0 To 15
Read ZNAK(I)
If I=0 Then ZNAKN(I) =&HFF Else ZNAKN(I)=ZNAK(I)
Next I
'============= Definice INTERRUPTU ===========================================
SetTick 1000,DEJCAS ' INTERRUPT each 1000mS
'----------------------------------------------------------- ------------------
READTIME ' First reading
'**************** MAIN *******************************************************
'----------------------------------------------------------- ------------------
' Pulse 0.001 means that Write Pulse is 1uS (10-6 sec)
Do
D= SPI(SPIREAD,SDATA,SCLK,&H80)
D= SPI(SPIREAD,SDATA,SCLK,CAS(0))
Pulse LWRITE,0.001
D= SPI(SPIREAD,SDATA,SCLK,&H40)
D= SPI(SPIREAD,SDATA,SCLK,CAS(1))
Pulse LWRITE,0.001
D= SPI(SPIREAD,SDATA,SCLK,&H20)
D= SPI(SPIREAD,SDATA,SCLK,CAS(2))
Pulse LWRITE,0.001
D= SPI(SPIREAD,SDATA,SCLK,&H10)
D= SPI(SPIREAD,SDATA,SCLK,CAS(3))
Pulse LWRITE,0.001
' L=L+1 ' PRO MERENI POCTU REFRESH - VYJMOUT APOSTROF
If CAS<>0 Then READTIME
Loop
End ' MAIN
'----------------------------------------------------------- -------------------
'*********************************************************** *******************
'=============*INTERRUPT SERVICE*=============================================
DEJCAS:
CAS=1
IReturn
'=========================================================== ===================
'SUBRUTINA PRO CTENI CASU, POUZIVA POUZE GLOBALNI PROMENNE, PROTO JE BEZ PARAM|
'----------------------------------------------------------- -------------------
Sub READTIME
CAS(3)=ZNAKN(Val(Left$(Time$,1))):CAS(2)=ZNAK(Val(Mid$(Time$ ,2,1))) And &H7F
CAS(1)=ZNAK(Val(Mid$(Time$,4,1))):CAS(0)=ZNAK(Val(Mid$(Time$ ,5,1))):CAS=0
'Print L;Chr$(13);: L=0 ' PRO MERENI POCTU REFRESH - VYJMOUT APOSTROF
Return
'======= DATA FOR 7-SEG DISPLAY =====================================
'Data &H80,&H40,&H20,&H10 'D1,D2,D3,D4
Data &HC0,&HF9,&HA4,&HB0,&H99,&H92,&H82,&HF8,&H80,&H90 '0-9
Data &H88,&H83,&HC6,&HA1,&H86,&H8E 'A-F

BobD

Guru

Joined: 07/12/2011
Location: Australia
Posts: 935

Posted: 05:19pm 23 Mar 2012

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boss said Can someone advise me why "COPY" command is so slow? In this case program is very short, but copy time takes incredible 25 sec.

boss

probably takes so long because you are copying to and from the SD card. The writes and the reads are competing for access to the card.

boss

Senior Member

Joined: 19/08/2011
Location: Canada
Posts: 268

Posted: 05:56pm 23 Mar 2012

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Yes, I was considering the same reason but still a copy time of more than 25 seconds seems be too long. Yesterday I tried to copy a ~5MB file and this lasted the whole night.

Geoffg

Guru

Joined: 06/06/2011
Location: Australia
Posts: 3194

Posted: 01:16am 01 Apr 2012

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I have had a look at the code and it is easy to see why it is slow... the copy is done on a byte by byte basis. Adding some buffering (2KB) made it run over 100 times faster.

I will put this in 3.2 (due in about 4 weeks).

Geoff

Geoff Graham - http://geoffg.net

boss

Senior Member

Joined: 19/08/2011
Location: Canada
Posts: 268

Posted: 02:43am 01 Apr 2012

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I thought so. Thank you for explanation.

boss

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