usb communication f28377s

David Bedolla

Other Parts Discussed in Thread: TMS320F28335, CONTROLSUITE

Hi,

I want to send and receive data between the PC and f28377s evaluation card.

In the Example_28377SLaunchPad demo, where STOUD is used for sending data to the PC (I have no problem with it), I have tried to receive data from de PC using STDIN, but I can't.

In the usb_dev_serial_cpu01 example, I think I have to buy a "Control Card". But I Just want to use the USB connection, I understand that the control card have the micro and mini usb connection available.

In the sci_echoback_cpu01 example. It says that I have to connect de GPIO28 and GPIO29 to a DB9 cable (I can’t find that pins), as I say I just want to use the USB connection. I think I have to change the boot mode with the switches, maybe it allows me to use SCIA via usb connection, but I’m not sure. I have seen that is used for programming the flash or booting the f28377s.

Editing the sci_echoback_cpu01 example I have tried to use de SCIB with the GPIO87 and GPIO86, but nothing appear in the oscilloscope.

In the chapter 9 of Texas Instruments teaching materials TMS320F2833x, I found an example, where the SCI is used with ISR, it doesn’t need any connections. I copied the code and tested it, there were some errors, but I fixed it quite easily, when I download the program nothing appear in the terminal, using putty, Hercules, terminal in code composer studio, Arduino monitor serie. I will let you the code if you want to check it.

If anyone can help me, telling me the way I don’t need to use an extra connection, or if it is possible share with me any simple code. I have spent days trying to receive a data from the PC.

// Lab9_4: TMS320F28335

// (c) Frank Bormann

//###########################################################################

// FILE: Lab9_4.c

// TITLE: DSP28 SCI - Communication to PC - Terminal

// SCI-Setup: 9600 Baud, 8 Bit , ODD Parity , 1 Stopbit

// SCI - TX and RX - Interrupt are used in this Lab

// SCI - TX and RX - FIFO are used in this Lab

// DSP waits for "Texas" and answers with "Instruments"

// Watchdog active , serviced solely in main-loop

//###########################################################################

// Ver | dd mmm yyyy | Who | Description of changes

// =====|=============|======|===============================================

// 3.0 | 08 Jul 2009 | F.B. | adapted for ControlCard28335 @ 20MHz

// 3.1 | 15 Nov 2009 | F.B | Lab9_4 for F28335 @30MHz and PE revision 5

//###########################################################################

#include "F28x_Project.h"

#include <string.h>

/*// External Function prototypes

extern void InitSysCtrl(void);

extern void InitPieCtrl(void);

extern void InitPieVectTable(void);*/

// Prototype statements for functions found within this file.

void Gpio_select(void);

void SCIA_init(void);

interrupt void SCIA_TX_isr(void); // SCI-A Transmit Interrupt Service

interrupt void SCIA_RX_isr(void); // SCI-A Receive Interrupt Service

// Global Variables

char message[]={" Instruments! \n\r"};

char buffer[16];

unsigned long int c1=0, c2=0;

//###########################################################################

// main code

//###########################################################################

void main(void)

{

InitSysCtrl(); // Basic Core Initialization

// SYSCLK=150MHz, HISPCLK=75MHz, LSPCLK=37.5MHz

EALLOW;

//SysCtrlRegs.WDCR= 0x00AF; // Re-enable the watchdog

WdRegs.WDCR.all = 0x00AF;

EDIS; // 0x00E8 to disable the Watchdog , Prescaler = 1

// 0x00AF to NOT disable the Watchdog, Prescaler = 64

Gpio_select(); // GPIO9, GPIO11, GPIO34 and GPIO49 as output

// to 4 LEDs at Peripheral Explorer

InitPieCtrl(); // default status of PIE; in DSP2833x_PieCtrl.c

InitPieVectTable(); // init PIE vector table; in DSP2833x_PieVect.c

// re-map PIE - entry for SCI-A-TX and SCI-A-RX

EALLOW;

//PieVectTable.SCITXINTA = &SCIA_TX_isr;

//PieVectTable.SCIRXINTA = &SCIA_RX_isr;

PieVectTable.SCIA_TX_INT = &SCIA_TX_isr;

PieVectTable.SCIA_RX_INT = &SCIA_RX_isr;

EDIS;

SCIA_init(); // Initalize SCI

// Enable SCI-A TX Interrupt Group9 interupt 2

PieCtrlRegs.PIEIER9.bit.INTx2 = 1;

// Enable SCI-A RX Interrupt Group9 interupt 1

PieCtrlRegs.PIEIER9.bit.INTx1 = 1;

// Enable INT9 for SCIA-TX and SCIA-RX:

IER = 0x100;

// Enable global Interrupts and higher priority real-time debug events:

EINT; // Enable Global interrupt INTM

ERTM; // Enable Global realtime interrupt DBGM

while(1)

{

EALLOW;

//SysCtrlRegs.WDKEY = 0x55; // Service watchdog #1

//SysCtrlRegs.WDKEY = 0xAA; // Service watchdog #2

WdRegs.WDKEY.bit.WDKEY = 0x55; //.bit.WDKEY

WdRegs.WDKEY.bit.WDKEY = 0xAA; //.bit.WDKEY

EDIS;

}

void Gpio_select(void)

{

EALLOW;

GpioCtrlRegs.GPAMUX1.all = 0; // GPIO15 ... GPIO0 = General Puropse I/O

GpioCtrlRegs.GPAMUX2.all = 0; // GPIO31 ... GPIO16 = General Purpose I/O

GpioCtrlRegs.GPAMUX2.bit.GPIO28 = 1; // SCIRXDA

GpioCtrlRegs.GPAMUX2.bit.GPIO29 = 1; // SCITXDA

GpioCtrlRegs.GPBMUX1.all = 0; // GPIO47 ... GPIO32 = General Purpose I/O

GpioCtrlRegs.GPBMUX2.all = 0; // GPIO63 ... GPIO48 = General Purpose I/O

GpioCtrlRegs.GPCMUX1.all = 0; // GPIO79 ... GPIO64 = General Purpose I/O

GpioCtrlRegs.GPCMUX2.all = 0; // GPIO87 ... GPIO80 = General Purpose I/O

GpioCtrlRegs.GPADIR.all = 0;

GpioCtrlRegs.GPADIR.bit.GPIO9 = 1; // peripheral explorer: LED LD1 at GPIO9

GpioCtrlRegs.GPADIR.bit.GPIO11 = 1; // peripheral explorer: LED LD2 at GPIO11

GpioCtrlRegs.GPBDIR.all = 0; // GPIO63-32 as inputs

GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1; // peripheral explorer: LED LD3 at GPIO34

GpioCtrlRegs.GPBDIR.bit.GPIO49 = 1; // peripheral explorer: LED LD4 at GPIO49

GpioCtrlRegs.GPCDIR.all = 0; // GPIO87-64 as inputs

EDIS;

}

void SCIA_init()

{

SciaRegs.SCICCR.all =0x0027; // 1 stop bit, No loopback

// ODD parity,8 char bits,

// async mode, idle-line protocol

SciaRegs.SCICTL1.all =0x0003; // enable TX, RX, internal SCICLK,

// Disable RX ERR, SLEEP, TXWAKE

// SYSCLOCKOUT = 150MHz; LSPCLK = 1/4 = 37.5 MHz

// BRR = (LSPCLK / (9600 x 8)) -1

// BRR = 487 gives 9605 Baud

//SciaRegs.SCIHBAUD = 487 >> 8; // Highbyte

//SciaRegs.SCILBAUD = 487 & 0x00FF; // Lowbyte

SciaRegs.SCIHBAUD.all = 487 >> 8; // Highbyte //.bit.BAUD

SciaRegs.SCILBAUD.all = 487 & 0x00FF; // Lowbyte //.bit.BAUD

SciaRegs.SCICTL2.bit.TXINTENA = 1; // enable SCI-A Tx-ISR

SciaRegs.SCICTL2.bit.RXBKINTENA = 1; // enable SCI_A Rx-ISR

SciaRegs.SCIFFTX.all = 0xC060; // bit 15 = 1 : relinquish from Reset

// bit 14 = 1 : Enable FIFO

// bit 6 = 1 : CLR TXFFINT-Flag

// bit 5 = 1 : enable TX FIFO match

// bit 4-0 : TX-ISR, if TX FIFO is 0(empty)

SciaRegs.SCIFFCT.all = 0x0000; // Set FIFO transfer delay to 0

SciaRegs.SCIFFRX.all = 0xE065; // Rx interrupt level = 5

SciaRegs.SCICTL1.all = 0x0023; // Relinquish SCI from Reset

}

// SCI-A Transmit Interrupt Service

interrupt void SCIA_TX_isr(void)

{

unsigned int i;

// copy 16 character into SCI-A TX buffer

//for(i=0;i<16;i++) SciaRegs.SCITXBUF= message[i];

for(i=0;i<16;i++) SciaRegs.SCITXBUF.all= message[i]; //SCITXBUF.bit.TXDT

// Acknowledge this interrupt to receive more interrupts from group 9

PieCtrlRegs.PIEACK.all = PIEACK_GROUP9;

c1++;

}

// SCI-A Receive Interrupt Service

interrupt void SCIA_RX_isr(void)

{

int i;

//for (i=0;i<16;i++) buffer[i]= SciaRegs.SCIRXBUF.bit.RXDT;

for (i=0;i<16;i++) buffer[i]= SciaRegs.SCIRXBUF.bit.SAR;

if (strncmp(buffer, "Texas", 5) == 0)

{

SciaRegs.SCIFFTX.bit.TXFIFOXRESET =1; // enable TXFIFO

SciaRegs.SCIFFTX.bit.TXFFINTCLR = 1 ; // force TX-ISR

}

SciaRegs.SCIFFRX.bit.RXFIFORESET = 0; // reset RX-FIFO pointer

SciaRegs.SCIFFRX.bit.RXFIFORESET = 1; // enable RX-operation

SciaRegs.SCIFFRX.bit.RXFFINTCLR = 1; // clear RX-FIFO INT Flag

PieCtrlRegs.PIEACK.all = PIEACK_GROUP9;

c2++;

}

//===========================================================================

// End of SourceCode.

//===========================================================================

over 9 years ago

0 Sal Pezzino over 9 years ago

TI__Mastermind 32995 points

Hi,

The USB module on the F2837x silicon is not exposed to the MiniUSB connector on the LaunchPad. You will need to use a Control Card which has a micro-USB connector which is connected to the USB module on chip. You may be able to use GPIO pin connections for USB communication on the Launchpad but I am not sure if the USB GPIO pins are pinned out on the LaunchPad.

The LaunchPad has GPIO 84/85 pinned out to the mini-USB connector. These pins are routed through an FTDI chip which enables serial (SCI/UART) communication through the USB connector to your PC.

To get sci_echoback working, change the pins from 28/29 to 84/85. You may also need to change the baudrate dividers if using the external oscillator (XTAL) because I think the LaunchPad uses a 10MHz external oscillator and the example in controlSUITE is designed for the controCard which uses a 20MHz external oscillator.

sal

0 Adam Wheeler over 9 years ago in reply to Sal Pezzino

Intellectual 270 points

Hi Sal,

I am trying to do the same thing I believe, and have the code working up to the point where I need to re-adjust the baud rates. According to the schematics, the crystal powering the FTDI is a 12MHz crystal, while the system clock seems to be the 10MHz crystal. Which of these are we supposed to use?

Thanks,
-Adam

0 Sal Pezzino over 9 years ago in reply to Adam Wheeler

TI__Mastermind 32995 points

It would depend on the SYSCLK and Low Speed Peripheral Clock. Please see the SCI chapter of the TRM. The Launchpad I believe has a 10MHz external crystal. It also as 2 internal oscillators at 10MHz. The LSPCLK is by default the SYSCLK / 4.

Hope this helps.

sal

0 Adam Wheeler over 9 years ago in reply to Sal Pezzino

Intellectual 270 points

Hi Sal,

Thank you for your response on this reasonably old topic. I configured GPIO73 on my F28377S LaundPad to be XTALOUT, with the SYSCLK selected and a divider of 1 (please see below):

EALLOW;
ClkCfgRegs.CLKSRCCTL3.bit.XCLKOUTSEL = 0; // Should set clock src to SYSCLK (200MHz)
ClkCfgRegs.XCLKOUTDIVSEL.bit.XCLKOUTDIV = 0; // Set divider to 1
GpioCtrlRegs.GPCMUX1.bit.GPIO73 = 3; // GPIO73 -> XTALOUT
EDIS;

However, when I probe GPIO73 (pin 12 on JP2), I see a 100MHz wave instead of my expected 200MHz. The SYSCLK should be 200MHz based on the comments I've read from the code (I am working with ControlSuite's echo_back example), and this portion here defines it pretty well:

//  Example:   200 MHz devices:
//             CLKIN is a 10 MHz crystal or internal 10 MHz oscillator
//
//             In step 1 the user specified the PLL multiplier = 40 for a
//             200 MHz CPU clock (SYSCLKOUT = 200 MHz).
//
//             In this case, the CPU_RATE will be 5.000L
//             Uncomment the line: #define CPU_RATE 5.000L
//

#define CPU_RATE   5.00L   // for a 200MHz CPU clock speed (SYSCLKOUT)

I have the XTAL_OSC oscillator selected (10MHz) an IMULT of 40, an FMULT of 0, and a PLLCLK_BY_2 which strangely has a value of 1

    //  PLLSYSCLK = (XTAL_OSC) * (IMULT + FMULT) / (PLLSYSCLKDIV)
    //
#ifdef _LAUNCHXL_F28377S
    InitSysPll(XTAL_OSC,IMULT_40,FMULT_0,PLLCLK_BY_2);

Do you know why I am seeing my SYSCLK output as 100MHz instead of my expected 200MHz?

0 Sal Pezzino over 9 years ago in reply to Adam Wheeler

TI__Mastermind 32995 points

I am not sure. I would suggest double-checking the TRM and bit definitions and what is being written to those registers by the set-up code.

If you cannot correct it, I suggest opening up another thread so it can be assigned to the more appropriate engineer here and the title would more accurately reflect the issue.

Thanks!
sal

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usb communication f28377s