A surface-charge shift register with digital refresh

A digital shift register using the surface-charge transistor structure in which adjacent rows propagate in opposite directions and which has refresh turn-around circuits at the ends of each row is described. Two process compatible refresh circuits requiring only four times the basic bit storage area have been designed, and a test circuit composed of two 16-bit shift registers that propagate in opposite directions and are connected by these circuits has been built and tested. The regeneration characteristics of these refresh circuits have been measured as a function of transfer time in both the complete and partial transfer modes (`fat zero'). Operation of one of these 32-stage shift registers and its refresh at 10 MHz is presented.