TCA6416A: Implementation details on the DSP(TMS320C6678)?

Krishn,

Krishn_JI said:

We want to know about the  TCA6416A implementation details. In this case,
We want to interface the LCD with the matrix Keypad on the TMS320C6678 EVM using the I2C Protocol.

Please guide us on "How to implement TCA6416A using I2C with TMS320C6678 EVM?" with Pins, TCA6416A's program sample and connections of pins etc.

I am not familiar with the TMS320C6678 operation, but I can comment on how to interface the TCA6416A with the 4x4 key pad scanner. 

I do want to offer the TCA8418E which is our i2c key pad scanner that has built in functionality for key pad arrays with features such as debounce and a 10 byte FIFO for action storage. The only problem I see is that TCA8418E is single supply, so current 1.8V to 5.0V level translation cannot work. 

TCA6416A can be used here, but things like debounce would need to be implemented externally with an RC like circuit on each of the INPUT/OUTPUT pins. 

/INT can be left floating (pin 1). 

Pin 3 needs an external pull-up resistor connected to VCCI or VCCP to prevent the /RESET pin from floating. 

Any Pxx pin that is left floating that is configured as INPUT needs a pull-up or pull down resistor to reduce increased ICC current leakage. The other option is to configure the floating Pxx pin as OUTPUT, then it can be left floating. 

From a software perspective, the TCA6416A follows the timing specifications for I2C in the I2C standard owned by NXP. 

Software implementation procedure to read and write from and to the TCA6416A begins on page 23 of the datasheet. 

Regards,

Tyler

Hi Krishn,

You're welcome. I will close the thread if no further questions. Please re-open if there are additional questions. 

Regards,

Tyler