Correct pin configuration/hardware setup for USB Host on Tiva Launchpad

Krithik Chandrashekar

Other Parts Discussed in Thread: EK-TM4C123GXL

I've already made the hardware changes as per the User's Guide, I've populated two 0-Ω's at R25 and R29.

As per the USB library user guide

"To properly configure host mode, the application must first configure and enable the host power

pins for USBEPEN and USBPFLT. These are configured using in the library the USBHCDPower-
ConfigInit(). The actual physical pins must also be enabled and configured by the application using
SysCtlPeripheralEnable() followed by GPIOPinTypeUSBDigital(). These pins are located on differ-
ent physical pins on devices and thus must be configured by the application. The remaining USB
pins are handled by the library and do not require any configuration. "

Will the below code suffice to setup USB host mode on the Tiva Launchpad or am I missing something? ALso, should I use GPIOPinTypeUSBAnalog or GPIOPinTypeUSBDigital?

SysCtlPeripheralEnable(SYSCTL_PERIPH_USB0);
SysCtlUSBPLLEnable();

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
GPIOPinTypeUSBDigital(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1);

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
GPIOPinTypeUSBDigital(GPIO_PORTD_BASE, GPIO_PIN_4 | GPIO_PIN_5);

USBHCDPowerConfigInit(0, USBTHCD_VBUS_AUTO_HIGH | USBHCD_VBUS_FILTER);

over 11 years ago

0 Amit Ashara over 11 years ago

TI__Guru**** 244400 points

Hello Krithik,

For the DP, DM, VBUS and ID pins it is GPIOPinTypeUSBAnalog. For the EPEN and PFLT pins it is GPIOPinTypeUSBDigital.

Regards

Amit

0 Krithik Chandrashekar over 11 years ago in reply to Amit Ashara

Intellectual 855 points

Hello Amit,

Do I have to configure the EPEN and PFLT pin(s)? The resistor R29 connects the USB VBUS signal to PB1. There isn't really an external power source for me to control on the launchpad. Consequently in this case, I also don't know what parameter to pass to the USBHCDPowerConfigInit() function.

I'm using the usb_host_msc example for the DK-TM4C123G board as a point of reference.

Thanks,
Krithik

0 Amit Ashara over 11 years ago in reply to Krithik Chandrashekar

TI__Guru**** 244400 points

Hello Krithik

if you are using the DK-TM4C123 then PB1 is connected directly to USB VBUS (and not via R29). Even in the example code the EPEN is being controlled by the configuration line

    //
    // Initialize the power configuration. This sets the power enable signal
    // to be active high and does not enable the power fault.
    //
    USBHCDPowerConfigInit(0, USBHCD_VBUS_AUTO_HIGH | USBHCD_VBUS_FILTER);

Regards

Amit

0 Krithik Chandrashekar over 11 years ago in reply to Amit Ashara

Intellectual 855 points

Amit,

I'm using the ek-tm4c123gxl, hence the question. I want the board to provide +5v on the J9 micro-usb (labeled DEVICE) connector in host mode. Is this possible?

0 Amit Ashara over 11 years ago in reply to Krithik Chandrashekar

TI__Guru**** 244400 points

Hello Krithik,

You mentioned the code from DK-TM4C123 so the natural assumption was that you are using DK-TM4C23. Now that you have mentioned that it is EK-TM4C123, you can see the +USB_VBUS is connecyed to the VB pin of connector and PB1 pin of the device. To get the power on this pin you can connect an external 5V power supply or if the current requirement is not going to exceed that of the Debug USB cable then connect H18 to H19

Regards

Amit

0 Krithik Chandrashekar over 11 years ago in reply to Amit Ashara

Intellectual 855 points

Amit,

Apologies for the confusion caused, my bad.

I've shorted H18 and H19, I don't think my current requirement is going to be very high. I'm simply connecting a usb flash drive on the device end. I'm assuming that I do not have to configure EPEN and PFLT, then?

Thanks,
Krithik

0 Amit Ashara over 11 years ago in reply to Krithik Chandrashekar

TI__Guru**** 244400 points

Hello Krithik,

Yes, then you do not need to configure EPEN and PFLT.

Regards

Amit

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Correct pin configuration/hardware setup for USB Host on Tiva Launchpad