The document discusses using the GPIO peripheral on the TMS320C6745 chip to blink an LED by configuring the GPIO pins as outputs and toggling the output data register. It also describes reading the state of DIP switches using the GPIO input data register and displaying the value. The program examples show initializing the GPIO registers, setting up the direction and output values for blinking an LED, and reading the input register to display the DIP switch values.

1. Blinking LED
Using
TMS320C6745
https://www.pantechsolutions.net/products/dsp-
dsc-boards/tms320c6745-tyro

2. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
Features of GPIO
The GPIO peripheral consists of the following
features
• Separate input/output registers
• All GPIO signals can be used as interrupt sources
• All GPIO signals can be used to generate events
to the EDMA.

3. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
Led Connection to C6745

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GPIO Registers

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GPIO Address

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GPIO Direction Registers (DIRn)
By default, all the GPIO pins are configured as inputs
(bit value = 1)
1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0
F 0 0 0
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
F F F F
0xF000FFFF

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GPIO Output Data Registers
(OUT_DATAn)
0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1
0 F F F
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0
0x0FFF0000
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0
0x00000000

8. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
STEPS FOR LED BLINKING
Declare two pointer variables for GPIO Direction register
and GPIO Data Register
Set Byte Address for GPIO Direction register and GPIO Data
Register
Configure GPIO as output in GPIO Direction Register
Configure Required Blinking data in GPIO Data Register

9. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
Set Base Address
• gpio_dir01 = (Uint32 *)0x01E26010;
• gpio_out_data01 = (Uint32 *)0x01E26014;
Configure Direction register as Output
*gpio_dir01 = 0xF000FFFF;
Configure Data register as Output
*gpio_out_data01 = 0x0FFF0000;

10. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
Program
#define Uint32 unsigned int
void DelayMs(Uint32 Ms);
void main()
{
Uint32 *gpio_dir01,*gpio_out_data01;
gpio_dir01 = (Uint32 *)0x01E26010;
gpio_out_data01 = (Uint32 *)0x01E26014;
*gpio_dir01 = 0xF000FFFF;
while(1)
{
*gpio_out_data01 = 0x0FFF0000;
DelayMs(100);
*gpio_out_data01 = 0x00000000;
DelayMs(100);
}
}
void DelayMs(Uint32 Ms)
{
Uint32 i;
while(Ms>0)
{
for(i=0;i<300000;i++);
Ms--;
}
}

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DIP SWITCH INTERFACE

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GPIO Input Data Registers (IN_DATAn)

13. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
Program
#define Uint32 unsigned int
Uint32 Value,i;
void DelayMs(Uint32 Ms);
void main()
{
Uint32 *gpio_in_data01,*gpio_out_data01,*gpio_dir01;
gpio_in_data01 = (Uint32 *)0x01E26020;
gpio_dir01 = (Uint32 *)0x01E26010;
gpio_out_data01 = (Uint32 *)0x01E26014;
*gpio_dir01 = 0xF000FFFF;
while(1)
{
Value = *gpio_in_data01;
*gpio_out_data01 = Value<<16;
DelayMs(100);
}
}
void DelayMs(Uint32 Ms)
{
Uint32 i;
while(Ms>0)
{
for(i=0;i<30000;i++);
Ms--;
}
}

14. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
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15. Technology beyond the Dreams™ Copyright © 2014 Pantech Prolabs India Pvt Ltd.
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