topic Re: Header documentation for SDK function TPM_SetupDualEdgeCapture in MCUXpresso SDK

Header documentation for SDK function TPM_SetupDualEdgeCapture

martinhowell1 — Thu, 28 Mar 2019 15:52:39 GMT

After a lot of debugging and peering at registers I found an incorrect and/or misleading comment in fsl_tpm.h for the function TPM_SetupDualEdgeCapture()

It reads:

/*!
* @brief Configures the dual edge capture mode of the TPM.
*
* This function allows to measure a pulse width of the signal on the input of channel of a
* channel pair. The filter function is disabled if the filterVal argument passed is zero.
*
* @param base TPM peripheral base address
* @param chnlPairNumber The TPM channel pair number; options are 0, 1, 2, 3
* @param edgeParam Sets up the dual edge capture function
* @param filterValue Filter value, specify 0 to disable filter.
*/
void TPM_SetupDualEdgeCapture(TPM_Type *base,
tpm_chnl_t chnlPairNumber,
const tpm_dual_edge_capture_param_t *edgeParam,
uint32_t filterValue);

I was trying to combine channels 2 and 3 so passed kTPM_Chnl_2 to the chnlPairNumber. I should have passed kTPM_Chnl_1!! The comment should probably read

/*!
* @brief Configures the dual edge capture mode of the TPM.
*
* This function allows to measure a pulse width of the signal on the input of channel of a
* channel pair. The filter function is disabled if the filterVal argument passed is zero.
*
* @param base TPM peripheral base address
* @param chnlPairNumber The TPM channel pair number; options are 0 to combine ch 0 and 1, 1 to combine ch 2 and 3, 2 to combine ch 4 and 5
* @param edgeParam Sets up the dual edge capture function
* @param filterValue Filter value, specify 0 to disable filter.
*/

Probably we shouldnt be using tpm_chnl_t for this parameter but define another type tpm_combine_chnl_t instead.

Re: Header documentation for SDK function TPM_SetupDualEdgeCapture

kerryzhou — Fri, 29 Mar 2019 05:40:35 GMT

Hi Martin Howell,

Please tell me what the kinetis chip you are using?

Please also let me know your SDK code name.

Waiting for your updated information.
Have a great day,
Kerry

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Re: Header documentation for SDK function TPM_SetupDualEdgeCapture

martinhowell1 — Fri, 29 Mar 2019 09:26:47 GMT

Sorry I should have said.

We are using the M4 core on the iMX7ulp CPU although I am sure the TPM module is common to many of your SOCs

The TPM driver version is given in fsl_tpm.h as:

#define FSL_TPM_DRIVER_VERSION (MAKE_VERSION(2, 0, 2)) /*!< Version 2.0.2 */

The SDK has been installed on my machine into a folder called:

SDK_2.2_EVK-MCIMX7ULP_M4

Is there any further info you need?

Re: Header documentation for SDK function TPM_SetupDualEdgeCapture

kerryzhou — Mon, 01 Apr 2019 10:47:10 GMT

Hi Martin Howell,

Thanks a lot for your updated information.

About the IMX7 problem, it's better to create the question in this area:

i.MX Processors

I am just the kinetis and the I.MXRT engineer.

So, please create a new question in the new area, or the next time you need to add the chip part number in the question title.

Have a great day,
Kerry

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