tcDspI2c2

Introduction

The tcDspI2c2 class is used to provide a consistent method to access devices via an instance of the MityDSP I2C (version 2) bus. Although tcDspI2c2 may be used directly by applications, it is usually used by higher-level classes to provide access to a specific device.

An instance of the tcDspI2c2 class is created by specifying the firmware base address of the core and the interrupt level used. This core supports specifying a level of gnAutoLevel, which automatically installs a vectored interrupt.

See also:

MityDSP::tcDspInterruptDispatch Class Reference

MityDSP::tcDspI2c2 Class Reference

Example

This is a simple example of tcDspI2cs creation and usage:

 {
     SEM_handle   MyClass::myDoneFlag;
     tcDspI2cs    *MyClass::myI2cs;

     void MyClass::doSomething(void)
     {
         int i;
         unsigned char writedata[5] = { 0x03, 0xDE, 0xAD, 0xBE, 0xEF };
         unsigned char readdata[4];
         unsigned int my_base_addr = 0xB0000200;

         // Assume device is EEPROM, a 7 bit slave device with 1 byte
         // subaddressing (the EPROM ADDRESS)
 
         unsigned char mySlave = 0x50;
 
         // create access to the I2C
         myI2c = new tcDspI2c2((void *)my_base_addr);

         // write data sequence (4 bytes to offset 0x3 of EEPROM)
         // DATA      (Sender)   (Bits)
         // Start     (MityDSP)  (1)
         // SlaveAddr (MityDSP)  (7) 
         // W         (MityDSP)  (1) 
         // Ack       (Slave  )  (1) 
         // 0x03      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // 0xDE      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // 0xAD      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // 0xBE      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // 0xEF      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // Stop      (MityDSP)  (1) 
         myI2c->write(mySlave, writedata, 5);


         // Perform an addressed read from offset 0x3
         // DATA      (Sender)   (Bits)
         // Start     (MityDSP)  (1)
         // SlaveAddr (MityDSP)  (7) 
         // W         (MityDSP)  (1) 
         // Ack       (Slave  )  (1) 
         // 0x03      (MityDSP)  (8)
         // Ack       (Slave  )  (1) 
         // Start     (MityDSP)  (1)
         // SlaveAddr (MityDSP)  (7) 
         // R         (MityDSP)  (1) 
         // Ack       (Slave  )  (1) 
         // 0xDE      (Slave  )  (8)
         // Ack       (MityDSP)  (1) 
         // 0xAD      (Slave  )  (8)
         // Ack       (MityDSP)  (1) 
         // 0xBE      (Slave  )  (8)
         // Ack       (MityDSP)  (1) 
         // 0xEF      (Slave  )  (8)
         // NAck      (MityDSP)  (1) 
         // Stop      (MityDSP)  (1)          
         myI2c->write_read(mySlave, writedata, 1, readdata, 4);

         // read the next four bytes (don't reset the address)
         myI2c->read(mySlave, slaveWord, 4);
     }
 
  }