LAUNCHCC3235MOD: Changing the ADC pins to GPIO pins

Hello Team,

I am working with CC3235SF's ADC and GPIO modules. I am using the ADC channels 1,2 and 3 which uses GPIO3(pin 58), GPIO4(pin 59) and GPIO5(pin 60) respectively.

I have configured these ADC modules and their pins accordingly in the *.syscfg of the project.

In my application, I want to use the ADC channels as and when required and, when the read_once() functionality is over I want to configure the pins mentioned above as GPIO and set them high/low as required.

I am performing the below steps:

1. ADC_Init()
2. ADC_open() => pass the CONFIG_ADC_x as per the user input for returning an ADC handle.

3. ADC_convert()

4. ADC_close() => Now, as per my understanding, this function sets the ADC pin for the mentioned module to the reset state. So, it becomes easy to change the pin functionality from analog to digital.

I am trying to set the pin to GPIO immediately after calling the ADC_close() function (the ADC pins are not configured in the GPIO section of the *.syscfg as the hardware is used).

For this I am using the following register access functions:   

• Supply clock to the peripheral                                                                                                                                                                                                                                                                 HWREG(ARCM_BASE + APPS_RCM_O_GPIO_A_CLK_GATING) = APPS_RCM_GPIO_A_CLK_GATING_GPIO_A_RUN_CLK_ENABLE;

               HWREG(ARCM_BASE + APPS_RCM_O_GPIO_B_CLK_GATING) = APPS_RCM_GPIO_B_CLK_GATING_GPIO_B_RUN_CLK_ENABLE;

               HWREG(ARCM_BASE + APPS_RCM_O_GPIO_C_CLK_GATING) = APPS_RCM_GPIO_C_CLK_GATING_GPIO_C_RUN_CLK_ENABLE;

               HWREG(ARCM_BASE + APPS_RCM_O_GPIO_D_CLK_GATING) = APPS_RCM_GPIO_D_CLK_GATING_GPIO_D_RUN_CLK_ENABLE;

               HWREG(ARCM_BASE + APPS_RCM_O_GPIO_E_CLK_GATING) = APPS_RCM_GPIO_E_CLK_GATING_GPIO_E_RUN_CLK_ENABLE;

• Set the pin as output                                                                                                                                                                                                                                                                                                                     uint32_t addr = OCP_SHARED_BASE + OCP_SHARED_O_GPIO_PAD_CONFIG_0 + 0x00000004 * io;

                HWREG(addr) = 0b000001100000;

                HWREG((GPIOA0_BASE + 0x00001000 * (io/8)) + GPIO_O_GPIO_DIR) |= 0x00000001 << (io%8);

• Update output drive of the pin to high

                uint32_t addr = OCP_SHARED_BASE + OCP_SHARED_O_GPIO_PAD_CONFIG_0 + 4 * io;

                HWREG(addr) |= 0b000000010000;

However, I am not getting HIGH voltage at the pins and also, I am not able to read the OCP_SHARED_O_GPIO_PAD_CONFIG_0 register even after providing the clock to the peripheral.

I have also tried to use the function MAP_PinTypeGPIO in rom_map.h.

Could someone please guide me through this.

Thank you.