Encoder - Programmable (MEMKey)

The MEMKey is a fully programmable keypad
encoder. Using a jumper, the MEMKey supports either
a simple serial communication protocol or the standard
PC/AT communication protocol. In either
communication mode, it can decode key matrixes of up
to 4 columns by 5 rows. The rows and columns can
be programmed to match the row-column configuration
of any off the shelf keypad.

The value returned by the MEMKey can be
programmed to any standard value. In addition, the
debounce time and typematic rate are fully
programmable. All programmable values are stored in
non-volatile memory so they are saved when power is
off.

When operating with the serial protocol, the
MEMKey communicates at 2400 baud, 8N1, LSB first,
asynchronous. This can be either a 1 wire or a 2 wire
interface. In addition, there are 64 bytes of EEPROM
memory which is made available to the user as
scratch pad space.

• 4 X 5 Matrix
• Programmable Rows and Columns
• Programmable key values
• PC/AT or Serial Output
• Automatic or polled key reporting
• Programmable debounce and typematic
  times
• 64 Bytes of user-accessible EEPROM
• Standard TTL levels
• No external components
• Easy-to-use SIP package