public static void InitializeCpuIO()
{
if (chipSelectPin == null)
{
chipSelectPin = GpioController.GetDefault().OpenPin(CS_PIN_NUM);
chipSelectPin.SetDriveMode(GpioPinDriveMode.Output);
chipSelectPin.Write(GpioPinValue.High);
}
Spi.InitSpi(); /* Initialize ports to control MMC */
}
/*-----------------------------------------------------------------------*/
/* Select the card and wait for ready */
/*-----------------------------------------------------------------------*/
static int select() /* 1:OK, 0:Timeout */
{
/* Set CS# low */
chipSelectPin.Write(GpioPinValue.Low);
Spi.RcvSpi(); /* Dummy clock (force DO enabled) */
if (wait_ready() > 0)
{
return(1); /* Wait for card ready */
}
deselect();
return(0); /* Failed */
}
/*-----------------------------------------------------------------------*/
/* Receive bytes from the card */
/*-----------------------------------------------------------------------*/
static void rcvr_mmc(
ref byte[] buff, /* Pointer to read buffer */
uint bc /* Number of bytes to receive */
)
{
int rxIndex = 0;
do
{
buff[rxIndex++] = Spi.RcvSpi(); /* Store a received byte */
}while (--bc > 0);
}
static byte CardType; /* b0:MMC, b1:SDv1, b2:SDv2, b3:Block addressing */
/*-----------------------------------------------------------------------*/
/* Transmit bytes to the card */
/*-----------------------------------------------------------------------*/
static void xmit_mmc(
byte[] buff, /* Data to be sent */
uint bc /* Number of bytes to send */
)
{
byte d;
int bufIndex = 0;
do
{
d = buff[bufIndex++]; /* Get a byte to be sent */
Spi.XmitSpi(d);
} while (bufIndex < bc);
}
/*-----------------------------------------------------------------------*/
/* Deselect the card and release SPI bus */
/*-----------------------------------------------------------------------*/
static void deselect()
{
chipSelectPin.Write(GpioPinValue.High);
Spi.RcvSpi(); /* Dummy clock (force DO hi-z for multiple slave SPI) */
}