The document discusses using GPIO pins on a TMS320C6745 processor to interface with LEDs and switches. It describes the GPIO peripheral features, how to connect an LED to the GPIO pins, the GPIO registers used to configure the pins as inputs or outputs and read/write values. It provides code to blink an LED by writing values to the output data register and read the state of switches by reading the input data register.

1. LED & Switch
Interface
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

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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;

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DIP SWITCH INTERFACE

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GPIO Input Data Registers (IN_DATAn)

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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--;
}
}

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?

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