The KB1 was designed as a universal AT and PS/2 keyboard interface chip that can be used as a functional block in embedded projects. The AT-PS/2 keyboard interface involves complex timing and scan-code decoding. Incorporating AT-PS/2 keyboard decoding software in your project's microcontroller can significantly increase the required program memory size and introduce timing problems. Instead of burdening your project's microcontroller with the AT-PS/2 keyboard interface, the KB1 provides an alternative solution for keyboard input. It can communicate with the Host via any of three standard serial interface protocols. Lucid Technologies' RDT64 terminal uses a KB1 for its keyboard interface. The KB1 manual is available for download on the Data & Documentation page.
The KB1 comes in a 14-pin DIP. Current consumption is < 3 mA at 5 volts.
The serial interface mode is pin-slectable.
In the UART mode communications is 8 bit, no parity, 1 stop bit (8N1). Baud rates of 9600 or 1200 are supported.
In the SPI mode the KB1 acts as a slave. Communication speed is determined by the master. SPI modes 0,1,2,3 are supported.
In the I2C (IIC) mode serial operation is at 100 kHz. The format of the pin-selectable seven bit address is: 010XXXX.