Diagnostic Test for Decrement Byte Counters
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Controller microcode is utilized to test a decrement byte counter. Such a counter is typically used on input/output (I/O) attachment cards in conjunction with a minimum number of module I/O pins. Referring to Figs. 1A and 1B, in operation counter 1 is loaded with a value by the microcode using the signal + Microcode Load with the bits + Load Bit Qo to Qn. The device logic decrements the counter to satisfy a particular function (e.g., determine when a block of data has been transmitted) and the device monitors for the condition that the counter has decremented to 0 to terminate the particular function by signal line -Count (CNT) = 0.