DESCRIPTION

The HEF4534B is a 5-decade ripple counter. The binary outputs of the decade counters are time-multiplexed by an internal scanner on four BCD outputs (O 0 to O 3 ). The selected decade is indicated by a logic HIGH on the appropriate digit select output (OS0: units, 1; OS 1 : tens,
10; OS 2 : hundreds, 10 2 ;OS 3 : thousands, 103; OS 4 : ten thousands, 10 4 ).
The binary outputs (O0to O3) and the select outputs (OS 0 to OS 4 ) are 3-state controlled via enable inputs EO andEOS respectively, allowing interface with other bus orientated devices. Cascading may be accomplished by using the carry out (TC). The counter is triggered by a LOW to HIGH transition on the decade clock (CPA) and is reset by a HIGH level on the master reset (MR).