# Creating a dual CPU project
- Open a new folder; not workspace
- Import project from `C2000Ware_26_01_00_00`: `driverlib/f2837xd/examples/dual/empty_projects/css`
- Change project names
  - `gpio_bitfield_cpu1`
  - `gpio_driverlib_cpu2`
- Change the `.c` files also
- Driverlib project does not require changes for compiling
- Bitfield project needs some additional compilation variables
  - Path type var named `C2000_Common` point to `/Users/gmarx/ti/C2000Ware_26_01_00_00/device_support/f2837xd/common/include`
  - Path type var named `C2000_Headers` pointing to `/Users/gmarx/ti/C2000Ware_26_01_00_00/device_support/f2837xd/headers/include`
- Also at `C2000 Compiler` and `Include Options` we should add the previous created vars as:
  - `${C2000_Common}`
  - `${C2000_HEaders}`
- Additionally at `C2000 Compiler` and `Predefined Symbols` add the entry:
  - `_DUAL_HEADERS`
- Additional source files must be added from `/Users/gmarx/ti/C2000Ware_26_00_00_00/device_support/f2837xd/common/source`:
  - `F2837xD_SysCtrl.c`
  - `F2837xD_usDelay.asm`
- Adding the file `F2837xD_GlobalVariableDefs.c`-data structure to map all peripherals- that is at `/Users/gmarx/ti/C2000Ware_26_00_00_00/device_support/f2837xd/headers/source/F2837xD_GlobalVariableDefs.c`
- Adding the GPIO file ...
- One last file must be included the `F2837xD_Headers_nonBIOS_cpu1.cmd` from the path `/Users/gmarx/ti/C2000Ware_26_00_00_00/device_support/f2837xd/headers/cmd/F2837xD_Headers_nonBIOS_cpu1.cmd` **we are using the nonBIOS option because the code will run in debug mode**
- However, the CPU2 has an issue at the `Predefined symbols`, we must change the name `CPU1` to `CPU2`


# GPIOs example
## CPU1 - Bitfield

```c
/*
Example project to handle GPIOs from both CPUs using 
bitfield and driverlib approaches, respectively on each CPU.
-------------
CPU1: GPIO22 and GPIO97 using bitfield
CPU2: GPIO52 using driverlib
*/


// Included Files
#include "driverlib.h"
#include "device.h"
#include "F28x_Project.h"


// Main
void main(void)
{
    // 1: init system
    InitSysCtrl();

    // 2: configure gpios
    EALLOW;
    //2.1: GPIO22:
    GpioCtrlRegs.GPAMUX2.bit.GPIO22 = 0; // pin as gpio
    GpioCtrlRegs.GPADIR.bit.GPIO22 = 1; // configured as output
    GpioCtrlRegs.GPACSEL3.bit.GPIO22 = 0; // cpu1 by default

    //2.2: GPIO52:
    GpioCtrlRegs.GPBMUX2.bit.GPIO52 = 0; // pin as gpio
    GpioCtrlRegs.GPBDIR.bit.GPIO52 = 1; // as output
    GpioCtrlRegs.GPBCSEL3.bit.GPIO52 = 2; //cpu2

    //2.3 GPIO 97:
    GpioCtrlRegs.GPDGMUX1.bit.GPIO97 = 0; // pin as gpio
    GpioCtrlRegs.GPDDIR.bit.GPIO97 = 1; // output
    EDIS;

    // 3: Change the gpios state
    // 3.1: gpioo22:
    GpioDataRegs.GPASET.bit.GPIO22 = 1; // set a logic 1 in the output
    // 3.2: gpio97:
    GpioDataRegs.GPDSET.bit.GPIO97 = 1; // set a logic 1 in the output
    // 4: Infinite loop

}


// End of file
```


## CPU2 - driverlib

The main code is:

```c
/*Gerardo Marx 
16th July 2026
GPIOs management with dual CPUs
----------------
CPU1: GPIO22 and GPIO97 using bitfield approach
CPU2: GPIO52 using driverlib approach

  |-----------|
  |           |
  |GPIO22     |
  |           |
  |  ----     |
  |GPIO97     |
  |           |
  |GPIO52     |
  |-----------|
*/

// Libraries and includes
#include "driverlib.h"
#include "device.h"

void main(void){
    // 1: init uc does not required for CPU2
    // 2: config gpios
    //GPIO_setPadConfig(52, GPIO_PIN_TYPE_STD);
    //GPIO_setDirectionMode(52, GPIO_DIR_MODE_OUT);
    //GPIO_setControllerCore()
    
    // 3: change state 
    GPIO_writePin(52, 1);
    
    // 4: finite loop
    for(;;)
    {
        // control task
    
    }
    
}
```


Pin type at `gpio.h` file
```c
//*****************************************************************************
//
// Values that can be passed to GPIO_setPadConfig() as the pinType parameter
// and returned by GPIO_getPadConfig().
//
//*****************************************************************************
#define GPIO_PIN_TYPE_STD       0x0000U //!< Push-pull output or floating input
#define GPIO_PIN_TYPE_PULLUP    0x0001U //!< Pull-up enable for input
#define GPIO_PIN_TYPE_INVERT    0x0002U //!< Invert polarity on input
#define GPIO_PIN_TYPE_OD        0x0004U //!< Open-drain on output
#endif
```

Files to explore and use with a second approach instead of `GPIO_writePin` you can use`HWREG` function:
- `hw_memmap.h`
- `hw_gpio.h`

Compilation error `GPIO_EnableUnbondedIOPullups`

- /Users/gmarx/ti/C2000Ware_26_00_00_00/device_support/f2837xd/common/include/F2837xD_GlobalPrototypes.h
- `F2837xD_Gpio.c`