Digital Electronics: Principles, Devices and Applications

342 Digital ElectronicsCLK120VccI02DQQ19Q7I13DQQ18Q6I24DQQ17Q5I3I456ANDORArrayDDQQQQ1615Q4Q3I57DQQ14Q2I68DQQ13Q1I79DQQ12Q0GND1011OE(b)Figure 9.35(continued).GAL 22V10 uses E 2 CMOS (electrically erasable CMOS) technology which allows the device tobe reprogrammable through the use of an electrically erasable (E 2 floating-gate technology andconsume much less power compared with bipolar 22V10 devices owing to the use of advanced CMOStechnology. The device specifies 100 erase/write cycles, a 50–75 % saving in power consumptioncompared with bipolar equivalents and a maximum propagation delay of 4 ns. Each of the outputlogic macrocells offers two primary functional modes, which include combinational I/O and registeredmodes. The type of mode (whether combinational I/O or registered) and the output polarity (whetheractive HIGH or active LOW) are decided by the selection inputs S 0 and S 1 , which are normallycontrolled by the logic compiler. For S 1 S 0 equal to 00, 01, 10 and 11, outputs are active LOW registered,active LOW combinational, active HIGH registered and active HIGH combinational respectively.