TM4C1294NCPDT: Access Spansion 1 Gbit Flash through SSI interface

Pavitra,

My colleagues are working exactly on a driver to control a Spansion (now Cypress) memory. Although our part number is different, the protocol might be the same... Our goal is to have it working by the end of next week.

Anyway, for now I can help with a piece of code that is surely working in SSI communication. This one talks to a 32-bit word sensor, getting a reply on the next cycle after sending a "frame command". The bus is configured at 7.5MHz.

	uint32_t frame = 0x0A0B0C0D;
	uint32_t rullRegister;	// 32-bit response from device

    frameHigh = frame >> 16;
    frameLow = frame & 0xFFFF;

    IntMasterDisable();
    GPIOPinWrite(gyroHW->hwFSSBase,gyroHW->hwFSSPin,0);				// Lower CSB
    SSIDataPut(gyroHW->hwSSIBase, frameHigh);						// Sends only the upper 16 bits
    SysCtlDelay((SYSTEM_CLOCK_HZ/(3*7500000)));
    while(SSIBusy(gyroHW->hwSSIBase));							// Flush first 16 bits
    SSIDataGet(gyroHW->hwSSIBase, &readCrap);						// Read useless data
    SSIDataPut(gyroHW->hwSSIBase, (frameLow));						// This sends the other 16 bits
    SysCtlDelay((SYSTEM_CLOCK_HZ/(3*7500000)));
    while(SSIBusy(gyroHW->hwSSIBase));							// Flush second 16 bits
    GPIOPinWrite(gyroHW->hwFSSBase,gyroHW->hwFSSPin,gyroHW->hwFSSPin);		// Raise CSB
    SSIDataGet(gyroHW->hwSSIBase, &readCrap);						// Read useless data
    GPIOPinWrite(gyroHW->hwFSSBase,gyroHW->hwFSSPin,0);				// Lower CSB
    SSIDataPut(gyroHW->hwSSIBase, frameHigh);						// Flush third 16 bits
    SysCtlDelay((SYSTEM_CLOCK_HZ/(3*7500000)));
    while(SSIBusy(gyroHW->hwSSIBase));							// Wait for bits to be flushed out
    SSIDataGet(gyroHW->hwSSIBase, &read16High);						// Read 16 bits
    SSIDataPut(gyroHW->hwSSIBase, frameLow);						// Flush last 16 bits
    SysCtlDelay((SYSTEM_CLOCK_HZ/(3*7500000)));
    while(SSIBusy(gyroHW->hwSSIBase));							// Wait for bits to be flushed out
    SSIDataGet(gyroHW->hwSSIBase, &read16Low);						// Read more data
    GPIOPinWrite(gyroHW->hwFSSBase,gyroHW->hwFSSPin,gyroHW->hwFSSPin);		// Raise CSB
    IntMasterEnable();

    readReg =  (read16High << 16) | read16Low;
    memcpy(fullRegister, &readReg, 4);

Hope this helps. If you can later collaborate with your Spansion results, that would be nice.

Bruno