apendix G

apendix G from electric circuit

3-54. Locate the line labeled RAM_SL at location D8 of the HC11D0 schematic. To get a HIGH level on that line, what level must the inputs to U8 be? 3-55. Locate the output pins labeled E and R/W on U1 of the HC11D0 schematic. During certain operations, line E goes HIGH and line R/W is then used to signify a READ operation if it is HIGH or a WRITE operation if it is LOW. For a READ operation, which line goes LOW: WE_B or OE_B? T 3-46. Another circuit constructed the same way as Figure P3-45 causes the logic probe to come on when the switch is in the down (0) position. Further testing with the probe shows that pins 2 and 3 of the NOR IC are both LOW. Is anything wrong? If so, where is the fault? 3-47. Your company has purchased several of the 7430 eight-input NANDs shown in Figure P3-47. List the steps that you would follow to determine if they are all good ICs. 3-51. If you wanted to check the power supply connections for the 8031 IC (U8) on the 4096/4196 circuit, which pins would you check, and what level should they be? 3-52. On the 4096/4196 sheet 1 schematic, there are several gates labeled U1. Why are they all labeled the same? 3-53. Describe a method that you could use to check the operation of the inverter labeled U4:A of the Watchdog Timer. Assume that you have a dual-trace oscilloscope available for troubleshooting. 3-54. Locate the line labeled RAM_SL at location D8 of the HC11D0 schematic. To get a HIGH level on that line, what level must the inputs to U8 be? 3-55. Locate the output pins labeled E and R/W on U1 of the HC11D0 schematic. During certain operations, line E goes HIGH and line R/W is then used to signify a READ operation if it is HIGH or a WRITE operation if it is LOW. For a READ operation, which line goes LOW: WE_B or OE_B