Hi All,
I have interfaced an MCP23S17 With TMS320F28069 MCU and I am able to write to the System and output is being generated accordingly on port pins but there is a problem while reading from the register, it is always Zero.
I have interfaced an MCP23S17 With TMS320F28069 MCU and I am able to write to the System and output is being generated accordingly on port pins but there is a problem while reading from the register, it is always Zero.
C:
void SPI_Init(void)
{
SpibRegs.SPIPRI.bit.TRIWIRE =1;//3-wire Mode
SpibRegs.SPICCR.bit.SPICHAR = 0x7; // 16-bit char bits
SpibRegs.SPICCR.bit.CLKPOLARITY = 0;
SpibRegs.SPICTL.bit.CLK_PHASE = 0;
SpibRegs.SPICTL.bit.MASTER_SLAVE = 1;
SpibRegs.SPICTL.bit.TALK = 1; // Enable master mode, normal phase,
// enable talk, and SPI int disabled.
SpibRegs.SPIBRR = 63; // 15 -> 1Mbps
SpibRegs.SPICCR.bit.SPISWRESET = 1; // Relinquish SPI from Reset
SpibRegs.SPIPRI.bit.FREE = 1; // Set so breakpoints don't disturb xmission
}
C:
Uint16 SPI0_Write(unsigned char data)
{
Uint16 Send=0;
SpibRegs.SPITXBUF=(data<<8);
while(SpibRegs.SPISTS.bit.INT_FLAG ==0) {} // Wait until data received
Send = SpibRegs.SPIRXBUF;
return Send;
}
C:
void setup_MCP23S17()
{
EALLOW;
GpioCtrlRegs.GPAMUX2.bit.GPIO20 = 0; // RESET
GpioCtrlRegs.GPADIR.bit.GPIO20 = 1; // GPIO23 = output
GpioCtrlRegs.GPAMUX2.bit.GPIO21 = 0; // CS
GpioCtrlRegs.GPADIR.bit.GPIO21 = 1; // GPIO6 = output
EDIS;
GpioDataRegs.GPADAT.bit.GPIO20=0;//RESET ENABLE
DELAY_US(100);
GpioDataRegs.GPADAT.bit.GPIO20=1;//RESET ENABLE
DELAY_US(1000);
MCP23S17_write(IOCON, 0x18);
MCP23S17_write(IODIRA, 0x00);
MCP23S17_write(IODIRB, 0xFF);
MCP23S17_write(GPPUA, 0x00);
MCP23S17_write(GPPUB, 0xF0);
MCP23S17_write(IPOLA, 0xFF);
MCP23S17_write(IPOLB, 0x00);
}
void MCP23S17_write(unsigned char address, unsigned char value)
{
GpioDataRegs.GPADAT.bit.GPIO21=0;//CS ENABLE
SPI0_Write(IO_DEVICE_ADDRESS_WRITE);
SPI0_Write(address);
SPI0_Write(value);
GpioDataRegs.GPADAT.bit.GPIO21=1;//CS DISABLE
}
Uint16 MCP23S17_read(unsigned char address)
{
Uint16 received_data = 0;
GpioDataRegs.GPADAT.bit.GPIO21=0;//CS ENABLE
SPI0_Write(IO_DEVICE_ADDRESS_READ);
SPI0_Write(address);
received_data=SPI0_Write(0);
GpioDataRegs.GPADAT.bit.GPIO21=1;//CS DISABLE
return received_data;
}
C:
Temp=SPI0_Read(GPIOB);
