TMS320F280049C: AIO and Input x bar

DTruex

Part Number: TMS320F280049C
Other Parts Discussed in Thread: LAUNCHXL-F280049C

Is it possible to connect an AIO pin to the input x-bar? The reference manual indicates that it is possible but there is no way to assign an AIO pin to the input x bar in TI PinMux tool.

The technical ref manual (SPRUI33A–November 2015–Revised December 2017) section 8.1 says:

The analog signals on this device are multiplexed with digital inputs. These analog IO (AIO) pins do not
have digital output capability. They are assigned to a single port:
• Port H consists of GPIO224-GPIO247

Same manual section 9.1 says:

The Input X-BAR has access to every GPIO and
can route each signal to any (or multiple) of the IP blocks previously mentioned.

TI PinMux input X bar pin number pull down menus do not show any of the AIO pins.

Thanks

over 7 years ago

0 Hossein Forouzani over 7 years ago

Genius 3030 points

Hi,

DTruex said:

Is it possible to connect an analog IO pin to the input x-bar?

The answer is NO. You can't connect any analog IO pin to x-bar and as you can see in the image below, GPIO pins only can be connected to input x-bar

DTruex said:

Is it possible to connect an analog IO pin to the input x-bar? The reference manual indicates that it is possible but there is no way to assign an AIO pin to the input x bar in TI PinMux tool.

Would you please refer to the paragraph that mentions " it is possible to connect an analog IO pin to the input x-bar"?

Related to what is indicated in the manual, The analog signals on this device are multiplexed with digital inputs and this doesn't mean that analog IO pins could be connected to the input x-bar.

I have captured a screenshot for you to show that the INPUTXBAR Pins are exactly GPIO pins.

Final conclusion(from section 9.1):

the Input X-BAR is used to route signals from a GPIO to many different IP blocks such as the ADC(s), eCAP(s), ePWM(s), and external interrupts. The Input X-BAR has access to every GPIO and can route each signal to any (or multiple) of the IP blocks previously mentioned. The digital input of AIOs are also available on the Input X-BAR.

If you want to know what exactly digital input of AIOs are, I should say, as I mentioned above these pins are just GPIO pins that the analog signals on this device are multiplexed with them.

I hope this helps you.

Regards,

Hossein

0 DTruex over 7 years ago in reply to Hossein Forouzani

Intellectual 710 points

Hossein, thanks for the response.

"The analog signals on this device are multiplexed with digital inputs and this doesn't mean that analog IO pins could be connected to the input x-bar."

I am not trying to connect an analog signal to the input X bar.

"The digital input of AIOs are also available on the Input X-BAR. "

THis is exactly what I am trying to do but it is not possible using the Pin Mux tool. The pin numbers that are assigned to the AIO pins are not in the pull down menu (pin 9 for instance for AIO 224 which is referred to as digital input 224 on ADC pin). Sorry if the nomenclature is confusing but it is straight from the data sheet.

0 Hossein Forouzani over 7 years ago in reply to DTruex

Genius 3030 points

"The analog signals on this device are multiplexed with digital inputs and this doesn't mean that analog IO pins could be connected to the input x-bar."

I am not trying to connect an analog signal to the input X bar.

Very good.

"The digital input of AIOs are also available on the Input X-BAR. "

THis is exactly what I am trying to do but it is not possible using the Pin Mux tool. The pin numbers that are assigned to the AIO pins are not in the pull down menu (pin 9 for instance for AIO 224 which is referred to as digital input 224 on ADC pin). Sorry if the nomenclature is confusing but it is straight from the data sheet.

I want to say that you are right and expect TI engineers to confirm this issue. Here we have two statements in TMS320F28004x Piccolo™ Microcontrollers

Technical Reference Manual, SPRUI33A:

1-The Input X-BAR is used to route signals from a GPIO to many different IP blocks such as the ADCs, eCAPs, ePWMs, and external interrupts ......

So it doesn't say some of GPIOs so that we can understand that Input X-BAR has access to every GPIO.

2-On the other hand, it is stated that "The digital input of AIOs are also available on the Input X-BAR."

If we compare these two statements with the table below, I think we can find a contradiction between them, because none of the digital input of AIOs is assigned to any of GPIOs, so that we can conclude that "The digital input of AIOs are also available on the Input X-BAR" is not correct because these SIGNALs don't come from GPIOs and this is the logical reason that we can't find digital input of AIO pin numbers under the menu of INPUTXBAR in TI PinMux.

As I found out, the PinMux is OK, but Technical Reference Manual needs to be changed and the statement "The digital input of AIOs are also available on the Input X-BAR" should be removed in the next TRM release.

I'll be happy if someone from TI documentation team sees this post and confirms or refutes my suspicion.

Thank you DTruex for putting this issue in front of my eyes.

Regards,

Hossein

0 DTruex over 7 years ago in reply to Hossein Forouzani

Intellectual 710 points

From my origional post:

"The technical ref manual (SPRUI33A–November 2015–Revised December 2017) section 8.1 says:

I agree with you that if this statement is factual it should be reflected in table 4-2 however I did not interpret their omission from table 4-2 to imply they are not mapped to GPIO since section 8.1 explicitly says that they are. Taken with the statement in 9.1 that says "the input x bar has access to every GPIO" it seems unambiguous that AIO digital inputs are available at the input x bar.

Thanks for your input. Hopefully someone from TI will respond today.

0 Vivek Singh over 7 years ago in reply to DTruex

TI__Guru** 113755 points

Hi,

Analog signals are not available on input x-bar. We'll check and if needed, add ore clarification in TRM. Thank you for your feedback.Update

[Update] Confirm from our Analog expert that Analog singles are connected to Input x-bar.

Regards,

Vivek Singh

0 DTruex over 7 years ago in reply to Vivek Singh

Intellectual 710 points

Hi Vivek, thanks for the reply.

"Analog signals are not available on input x-bar. We'll check and if needed, add ore clarification in TRM. Thank you for your feedback."

Since my question is NOT about connecting an analog signal to the input x bar can you please clarify your statement? Again I am trying to connect AIOnnn, defined by TI as a "digital input nnn on ADC pin".

Thanks

0 Vivek Singh over 7 years ago in reply to DTruex

TI__Guru** 113755 points

Hi,

Even though you are using Analog pin as digital input, these are not connected to input x-bar so you can not use it these signals as input to x-bar.

Regards,

Vivek Singh

0 DTruex over 7 years ago in reply to Vivek Singh

Intellectual 710 points

Vivek Singh said:

Hi,

Even though you are using Analog pin as digital input, these are not connected to input x-bar so you can not use it these signals as input to x-bar.

Regards,

Vivek Singh

The answer above is not correct. I purchased a LAUNCHXL-F280049c board and wrote some software that toggles an output pin at 500 hz. I then connected this pin to ADCINA5 (AIO234). The code below uses Driverlib to configure AIO223 as the input to XINT1. Running this code shows that you can generate an XINT using AIO234 as the input.

   //try it on an analog pin
    GPIO_setAnalogMode(234U, GPIO_ANALOG_DISABLED);
    GPIO_setPinConfig(GPIO_234_GPIO234);
    GPIO_setMasterCore(234U, GPIO_CORE_CPU1);
    GPIO_setDirectionMode(234U, GPIO_DIR_MODE_IN);
    GPIO_setPadConfig(234U, GPIO_PIN_TYPE_STD);
    GPIO_setInterruptPin(234U, GPIO_INT_XINT1);

    GPIO_setInterruptType(GPIO_INT_XINT1, GPIO_INT_TYPE_BOTH_EDGES);
    GPIO_enableInterrupt(GPIO_INT_XINT1);

    XBAR_setInputPin(XBAR_INPUT4, 234U);
    Interrupt_register(INT_XINT1, &xInt1ISR);
    Interrupt_enable(INT_XINT1);
}
//
// xInt1ISR -
//
__interrupt void
xInt1ISR(void)
{
    xInt1IntCount++;

    //
    // Acknowledge this interrupt to receive more interrupts from group 1
    //
    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP1);
}

This shows to my satisfaction that AIO224 -246 are assigned to GPIO224-246 as stated in SPRUI33A section 8.1 and GPIO224-246 are available at the input x-bar as stated in section 9.1.

0 Vivek Singh over 7 years ago in reply to DTruex

TI__Guru** 113755 points

Hi DTruex,

Sorry, look like I had misunderstanding of this. You are right. It's available on input XBAR. I'll update my response.

Regards,

Vivek Singh

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TMS320F280049C: AIO and Input x bar