9/30/2020 0 Comments Usb Vs Spi
I need a price of at least 2 MBs, if it is definitely not possible with SD Credit card or SPI after that what are usually the options Any assist is highly appreciated.For attention, I just do a fast test, making use of Photo32 Beginner Kit with IO expansion board, inexpensive 16MT MMC credit card (which emerged with an old Canon surveillance camera), and standard Microchip SDMMC library.Processor swiftness was arranged to 80MHz, peripheral tour bus divisor has been arranged to OSCPBDIV2, and I used 2nd SPI route.
Composing 16-byte pieces, 1MByte in total, demands 10309 milliseconds, which gaves 800kparts per securities and exchange commission's. ![]() Usb Vs Spi Code Had BeenThe check code had been pretty simple: for (i actually0;i So there is definitely a great deal of area for finé-tuning in bóth the program code and in SDMMC collection. Your test results got been helpful for me to body out what can be done. I have just purchased a PIC32 USB beginner kit and enlargement board. Either you have to use Microchips PICTail board for SDMMC, or you have got to link another one to your growth board. I will use the sd trolley slot machine on an another growth table for dsPIC collection. The config registers in the code are usually: if defined (Picture24F) CONFIG2(IESOOFF FNOSCPRIPLL FCKSMCSDCMD OSCIOFNCOFF POSCMODHS) CONFIG1(JTAGENOFF GCPOFF GWRPOFF COEOFF ICSPGx2 FWDTENOFF) When I observe the SCLK pin itself on the SD little girl card, I observe just bursts of 8 parts at about 1.33MHz clock rate (0.75usec shift clock period). General - a long read operation of a 282KB file requires about 11 securities and exchange commission's, implying only a 200kbs rate or 25 kBs. ![]() SPICON1 0xFFFB; make use of 1:1 on PRI and 2:1 on SEC for 8MHz highest rate. SPICON1parts.SPRE2 1; 2:1 supplementary SPICON1bits.SPRE1 1; SPICON1pieces.SPRE0 0; SPICON1bits.SPRE0 1; attempt illegal 1:1 setting SPICON1parts.PPRE1 1; 1:1 main SPICON1bits.PPRE0 1; When I try to make use of the unlawful setting of 1:1 and 1:1 or 16MHz, I see the SPI clk pin number running at twice the rate above, but still only at about 2.7MHz. Whats incorrect The SPI clock seems no place near the intended frequency. My program requires a least of 1Mbs rate for enjoying back an sound file. I know there is definitely a lot of over head expected to the File program and SD methods, but has anyone approached that rate on Picture24 reading through SD Thanks. Whats the technique to enhancing the rate Applying the SD Shuttle bus proprietary 4-little bit protocol. Another matter Ive observed is that there will be a huge difference between the time it will take for a Excess fat32 card to initialize versus a Fats16 credit card. SD takes 3-5 seconds whereas an SDHC can take 20-40 seconds to show up as a navigable volume in Home windows once inserted. Breeze (PIN 8) SWDI. ATSAMR34-XPRO and MPLAB Bite Tool.
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