spi clock problem

RE: spi clock problem

john kotkin — Mon, 27 Jul 2015 03:05:19 GMT

Thank you, Yes the problem was because of two register i was trying to read return always Zero's

RE: spi clock problem

nszmnsky — Mon, 27 Jul 2015 01:03:56 GMT

I haven't used your flash, and I have only browsed the datasheet. Is it possible that the 0x05 should read register 1 would return all zero's? Try changing command to 0x90 to read the Manufact./Dev. ID (looks like would also need to change code to read 6 bytes) and see if you get correct data out.

I'd also suggest double checking pins - MOSI connected to DI, MISO to DO, and that /WP and /HOLD are pulled high.

RE: spi clock problem

john kotkin — Sun, 26 Jul 2015 07:53:03 GMT

I made this change and still nothing from w25q64fv, i changed my w25q64fv with a new one but still nothing

RE: spi clock problem

nszmnsky — Sun, 26 Jul 2015 04:31:09 GMT

The data sheet shows a 3 byte transaction, 1 byte command transmit and two byte receive. But to read a byte, you actually need to transmit one as SPI is a synchronous protocol. I think if you modify the code

uint8_t rx_data[3];

uint8_t tx_data[3] = {0x05, 0xff, 0xff};

spi_master_send_recv(SPI_MASTER_0, tx_data, 3, &rx_data, 3);

you should see 24 clocks, i.e. 3 byte send/receive. Of course you will also want to change function type and return IF you want 16bit integer.