Thanks Kai! I wasn't suitably motivated to do the numbers! I was always told that creating a delay with R & C was BAD! As to why that is so I was never told. In the 70's when cpus were made out of ttl I saw plenty of times where designers chucked in some C and maybe some R and if they wanted a big delay then we would see 7414s. In the 80's we had z80's and dynamic ram. Many designs I saw (we're talking large production here) used some R & C to do the ras/cas delays. No doubt delay lines are good for tight timing delays but we don't see them too often today. On today's motherboards we usually see squiggly tracks to correct timing skew.

Oleg suggested to old trick of using a latch rather than a register - fine if the outputs are running leds as our eyes will never see the glitches but can cause lots of fun if you have counters or flip/flops on the outputs.

I'd hate to think of the number of times I've been caught by 'simple' circuits. It all worked on the bench but come to production these timing issues raise their heads. It always pays to do the numbers!