Hello folks.
I have to serially string together three of these really nifty 74xx595 serial/parallel shift registers.
Here's the data sheet:
A fellow engineer warned me that if I do that I could be losing the 8th bit on each chip. It was something about the serial output bit being the same as the last bit register, so, the first bit on the next '595 would have to be the same. Apparently he had to hack a board to fix this once upon-a-time, though he speculated that he was following the serial output with a display driver chip not another 595.
I'm not seeing it... I think I won't lose the last bits of each shift register. What do you know about it?
In a related question why are they calling this serial output QH[red]'[/red] ?? That sounds like it would be inverted but the two bubbles in that output chain should cancel to give a non inverted output. What am I missing in this "[red]'[/red]" nomenclature? Is that just meaning "next in time" and not inversion?
Keith Cress
kcress -
I have to serially string together three of these really nifty 74xx595 serial/parallel shift registers.
Here's the data sheet:
A fellow engineer warned me that if I do that I could be losing the 8th bit on each chip. It was something about the serial output bit being the same as the last bit register, so, the first bit on the next '595 would have to be the same. Apparently he had to hack a board to fix this once upon-a-time, though he speculated that he was following the serial output with a display driver chip not another 595.
I'm not seeing it... I think I won't lose the last bits of each shift register. What do you know about it?
In a related question why are they calling this serial output QH[red]'[/red] ?? That sounds like it would be inverted but the two bubbles in that output chain should cancel to give a non inverted output. What am I missing in this "[red]'[/red]" nomenclature? Is that just meaning "next in time" and not inversion?
Keith Cress
kcress -