Diagnostic Facility for a Print Control System
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-04
A diagnostic scan facility provides means for recording the status of eight or sixteen signals at selected recording rates. The scan facility has means for recording the status of any one signal at a different rate. The choice of signals, recording rate and length of recording time is controlled by a microprogram. As seen in the drawing, register A receives 8-bit scan control words on bus 10 from a microprocessor (MP). Decode 11 decodes bits 0-3 of the control words to provide byte selection signals for gating byte status signals on buses 12 through byte select gates 13 onto output bus 14 to register B. Decode 15, when enabled by the "ON" bit 4 of the control word in register A, decodes bits 5-7 to provide a bit selection signal for gating a single status bit of a status byte on output bus 14 into register B.