SCLS815A July 2020 – December 2021 SN74HCS259-Q1
PRODUCTION DATA
The SN74HCS259-Q1 has four modes of operation. In this application, the 8-line demultiplexer mode is used to send data to one of eight possilbe desinations.
At system power-on, latched outputs are in an unknown state. The CLR input is held low while the G input is held high to clear the latches for operation. At this time, all outputs are in the low state.
An output is selected by setting S2, S1, and S0 as per the Latch Selection Table. After selection, the channel is activated by switching G to low. The logic value at the D input will appear at the selected output, allowing data transmission only to the selected device.
When the channel communication is complete, the G input is set to high to prevent erronous outputs while the address inputs are changed, then switched back to low again to send data to the newly selected device.