The IN74ACT193 is identical in pinout to the LS/ALS192, HC/HCT192. The IN74ACT193 may be used as a level converter for interfacing TTL or NMOS outputs to High Speed CMOS inputs. The counter has two separate clock inputs, a Count Up Clock and Count Down Clock inputs. The direction of counting is determined by which input is clocked. The outputs change state synchronous with the LOW-to-HIGH transitions on the clock inputs. This counter may be preset by entering the desired data on the P0, P1, P2, P3 input. When the Parallel Load input is taken low the data is loaded independently of either clock input. This feature allows the counters to be used as devide-by-n by modifying the count lenght with the preset inputs. In addition the counter can also be cleared. This is accomplished by inputting a high on the Master Reset input. All 4 internal stages are set to low independently of either clock input.Both a Terminal Count Down (TCD) and Terminal Count Up (TCU) Outputs are provided to enable cascading of both up and down counting functions. The TCD output produces a negative going pulse when the counter underflows and TCU outputs a pulse when the counter overflows. The counter can be cascaded by connecting the TCU and TCD outputs of one device to the Count Up Clock and Count Down Clock inputs, respectively, of the next device. TTL/NMOS Compatible Input Levels Outputs Directly Interface to CMOS, NMOS, and TTL Operating Voltage Range: 4.5 to 5.5 V Low Input Current: 1.0 A; 0.1 A @ 25C Outputs Source/Sink 24 mA