1. Presentation by Anthony Dotterer
EDE1144 Hex Pad Encoder
Presentation by Anthony Dotterer 4
Parallel
Device 1 1
Serial
Device 4 1

2. The Chip Layout
The EDE1144 keypad encoder reads a standard 4X4 keypad and a outputs a location value of the button in question
There are two ways that the keypad encoder can output the button pressed: parallel load and serial load

3. Serial Load Timing control Receiving Device Open
The used the RS-232 output pin to send the serial output. Combined with the data valued output and the Baud input the keypad encoder can send information via serial connection.
This serial connection differs from our familiar keyboard load in that, instead of outputting a clock signal, this circuit outputs a done signal and takes a BAUD rate input.
The circuit assumes that the receiving circuit has some kind of BAUD timer that can time the input of the data.
Open

4. Parallel Load Layout 4-bit FF’s Beeper Inverter Open
Form my circuit I chose to use the parallel load feature which is a bit easier to use then the serial load.
The parallel load involves pin 6 to pin 9 ( the row outputs ) and pin 17 ( data valid ).
The parallel load works by taking the information gathered and sending it along the row output pins. During this time the data valid signal will drop to zero and stay there for about 50ms. After 50ms the data valid signal will return to one as well as the row output pins.
4-bit FF’s
CLK 4 7
Seven Segment Display
Hex to Seven Display

5. Output
The output value of the keypad encoder is the location value of the button pressed
The output of the keypad encoder relies on the position of the button pressed.
This is in place to add more compatibility to the device, and to make the complexity of this device simpler.

6. The Absolute Ranges