IO Function Switching

dwarnke · ‎2014-07-15

Posted on July 15, 2014 at 21:38

I have a project that requires an IO pin to switch between High Z (Tri-State) and High. On a previous 8 bit micro the high z condition was satisfied by setting the port to an input and the high was satisfied by making the port and output and driving it high.

I am using the Hal drivers for non-OS and am strugglinig to find the commands to do this. I tried doing the following with o results:

// Set Charge to Output and Set High

palSetPadMode(PORT_B, CHARGE, PAL_MODE_OUTPUT_PUSHPULL);

palSetPad(PORT_B, CHARGE);

// Delay 5us

//osalThreadSleepMicroseconds(CHARGE_WAIT);

osalThreadSleepMicroseconds(50000);

// Set Charge to Input and set to high z

palSetPadMode(PORT_B, CHARGE, PAL_MODE_INPUT);

I played with different delay lengths thinking the scope missed it.

Please let me know if you have any ideas.

Doug

#spc56

Erwan YVIN · ‎2014-07-17

Posted on July 17, 2014 at 17:54

Hello Doug ,

Sorry , at the current time, pal_lld_setpadmode is not implemented (cf pal_lld.h)

/**

* @brief Pad mode setup.

* @details This function programs a pad with the specified mode.

* @note The @ref PAL provides a default software implementation of this

* functionality, implement this function if can optimize it by using

* special hardware functionalities or special coding.

* @note Programming an unknown or unsupported mode is silently ignored.

*

* @param[in] port port identifier

* @param[in] pad pad number within the port

* @param[in] mode pad mode

*

* @notapi

*/

#define pal_lld_setpadmode(port, pad, mode)

we need to write the PCR register in this case.

it is a change request in PAL LLD side.

Best Regards

Erwan

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Erwan YVIN · ‎2014-07-17