Hades logoHades applet banner
parallel-in serial-out shift-register

applet icon

The image above shows a thumbnail of the interactive Java applet embedded into this page. Unfortunately, your browser is not Java-aware or Java is disabled in the browser preferences. To start the applet, please enable Java and reload this page. (You might have to restart the browser.)

Circuit Description

A parallel-load serial-out shift-register.

Use mouse-clicks or type the bindkeys 'c' and 'e' to control the clock and enable (load/nshift) inputs, and the bindkeys '0' .. '7' to control the data inputs.

All flipflops are connected to the same clock and reset signals. and are sensitive to the rising-edge of the clock signal. The multiplexers are controlled via the 'LOAD/nSHIFT' input. When 'LOAD/nSHIFT' is high during the rising-edge of the clock, the flipflops are loaded with the parallel input data. When 'LOAD/nSHIFT' is low during the rising-edge of the clock, the multiplexers connect subsequent stages, so that the register contents is shifted by one bit-position.

The default value on an idle RS-232 serial communication channel is high, while the start bit is low. This explains the constant input values for the first (bottom-most) flipflops. The next eight flipflops provide the actual input data, with the least-significant bit transmitted first. The next flipflops provide the optional parity bit and the required extra stop bit.

Print version | Run this demo in the Hades editor (via Java WebStart)
Usage | FAQ | About | License | Feedback | Tutorial (PDF) | Referenzkarte (PDF, in German)
Impressum http://tams.informatik.uni-hamburg.de/applets/hades/webdemos/45-misc/30-uart/shifter.html