sequential (12) preset clear
https://wodewangzhishime.blogspot.com/2022/01/httpswodewangzhishime_72.html . Ref: https://wodewangzhishime.blogspot.com/2022/01/httpswodewangzhishime_45.html . There're 5 conditions on which left or right shift doesn't work. . 1) The latch is being preset and clear. 2) The latch is feedbacking. 3) The latch is being level-trigger. 4) The flip flops is at the stage of toggling. 5) The commutator is idle. . No up cycle. . No down cycle. . . . John: Now, we mention condition_1. . That mean, presetting and clearing. Presetting and clearing are independent from the clock line. That mean, . 1) The clock line is at the up cycle. . I can preset and clear it. 2) The clock line is at the down cycle. . I can preset and clear it. . . Note: Left or right shift are based on triggering. . Triggering is based on clock line. . If no clock line is involed, there is no triggering, consequently, there is no left or right shift.