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USB EZ-PD Type-C

Contributor II

/**

* @brief This function checks if power is present on VBus

*

* @param port Port index the function is performed for.

* @param volt Voltage in mV units.

* @param per  Threshold margin.

*

* @return true if power is present on VBus, else returns false

*/

bool vbus_is_present(uint8_t port, uint16_t volt, int8_t per);

/**

* @brief This function gets the ADC level that corresponds to the actual

* voltage on vbus. It also takes into account the VBus monitor divider.

*

* @param port Port index. Caller should ensure to provide only valid values.

* @param adc_id ADC ID.

* @param volt Voltage in 50mV units.

* @param per Percentage margin on the voltage.

* @return Returns the ADC level.

*

* <B>Applicable devices:</B> CCG3, CCG4, CCG5, CCG3PA, CCG3PA2, CCG5C, CCG6.

*/

uint8_t pd_get_vbus_adc_level(uint8_t port, PD_ADC_ID_T adc_id, uint16_t volt,

        int8_t per);

/**

* @brief This function gets the current comparator status.

*

* This function does not configure the ADC / comparator. It just returns the

* current state of the comparator. If true is returned, then the input voltage

* is greater than the reference and if false, the input voltage is lower than

* the reference.

*

* @param port Port index. Caller should ensure to provide only valid values.

* @param adc_id ADC ID.

* @return Returns the comparator output.

*

* <B>Applicable devices:</B> CCG3, CCG4, CCG5, CCG3PA, CCG3PA2, CCG5C, CCG6.

*/

bool pd_adc_get_comparator_status(uint8_t port, PD_ADC_ID_T adc_id);

vbus_is_present function  call pd_get_vbus_adc_level  and to pd_adc_get_comparator_status

    /*

     * Re-run calibration every time to ensure that VDDD or the measurement

     * does not break.

     */

    pd_adc_calibrate (port, APP_VBUS_POLL_ADC_ID);

    level = pd_get_vbus_adc_level(port, APP_VBUS_POLL_ADC_ID, volt, per);

    retVal = pd_adc_comparator_sample (port, APP_VBUS_POLL_ADC_ID, APP_VBUS_POLL_ADC_INPUT, level);

    #if APP_SDK_FUNC_MSG_VALUE

    WEIZ_DEBUG_PRINT(WZ_GEN_SDK_FLOW, "[%s] %x < APP_VBUS_POLL_ADC_INPUT  %d\r\n", __func__,level*50,retVal);

    #endif

in debug message  i multiply level by 50 because  * @param volt Voltage in 50mV units.

result on CY4532  EVK  board base on CYPD3171

[FUNC]: [vbus_is_present] 190 < APP_VBUS_POLL_ADC_INPUT  0

[FUNC]: [vbus_is_present] 7d0 < APP_VBUS_POLL_ADC_INPUT  1

[FUNC]: [vbus_is_present] 7d0 < APP_VBUS_POLL_ADC_INPUT  1

[FUNC]: [vbus_is_present] bea < APP_VBUS_POLL_ADC_INPUT  0

[FUNC]: [vbus_is_present] e42 < APP_VBUS_POLL_ADC_INPUT  1

Q1 : i do not understand  what  vbus_is_present  check VDDD or VBUS ?

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1 Solution
Moderator
Moderator

Hi,

According to PD spec,

pastedImage_0.png

Min value-4.75V

Max value-5.5V

Best Regards,

Mallika

Mallika

View solution in original post

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3 Replies
Moderator
Moderator

Hi,

vbus_is_present() checks for VBUS, whether it is present within a specific range.

Regards,

Mallika

Mallika
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Contributor II

what is the range ?  by spec 4.75 -5.25 ?

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Moderator
Moderator

Hi,

According to PD spec,

pastedImage_0.png

Min value-4.75V

Max value-5.5V

Best Regards,

Mallika

Mallika

View solution in original post

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