74HC Datasheet, 74HC stage Binary Counter Datasheet, buy 74HC, 74HC pdf, ic 74HC description/ordering information. The ‘HC devices are stage asynchronous binary counters, with the outputs of all stages available externally. A high. Data sheet acquired from Harris Semiconductor. SCHSD. Features. • Fully Static Operation. • Buffered Inputs. • Common Reset. • Negative.

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All these numbers involving multiples of propagation-delays are making me question even further how I got the ol’ LCD controller running. This could be dtasheet.

74HC4040 Datasheet PDF

The 74hv4040 address can be updated from the horizontal sync. Yes, delete it Cancel. They’re not completely general anymore, since now they assume standard corner pin supply connections, but they should be better for signal integrity.

Monitors can handle some clock frequency variations.

Synchronization is an issue, but it’s worth thinking about – maybe if the PIC runs from the external I have to go take them out of my shopping cart now: Since it’s a datasneet counter, Q0 flips, then Q1, then Q2, etc, so we have to add all the delays so see how long it takes for the address to settle to the next value.

Let’s run the numbers, using a 15pF load: In this case, dtaasheet not memory but registers.


I’m using typical values for the moment; if it doesn’t work there, it’s not going to work worst-case, either. Did I miss something on the ripple counters? If I’m reading the datasheet correctly, the maximum delay from clock edge to valid outputs is Here’s a simplified schematic of the guts of the VGA framebuffer it ignores the reset and connections between the two ”s required to generate 19 bits of address. Synchronous counters use extra logic to form the next state from the previous one directly, without waiting for clocks to ripple through, so the outputs settle faster.

Add in the 12 ns access time of the SRAM, and we’re definitely over budget. How about the 74HC? Don’t forget that ground-bounce!

74HC Datasheet(PDF) – NXP Semiconductors

Yeah, I had read about keeping video blanked outside of the active area. For Qd the fourth bitthe typical tpd is given as 8. I saw the 25 MHz datxsheet in your terminal project – good to know.

I need 5 of them, which sucks. Sign up Already a member?

I can hook one to the four-channel scope and have a look at the delays between the LSB and successive bits. I’m going to ignore those timing calculations for the moment next log because there’s an even bigger problem here – it daatsheet too long for the address to settle.

74HC data sheet datasheet & applicatoin notes – Datasheet Archive

The 74hc40440 input on the ‘ works on the positive edge, so the schematic above changes a bit, but at least the addresses seem OK. Next step – the rest of the logic and timing calculations. Synchronous Counters Synchronous counters use extra logic to form the next state from the previous one directly, without waiting for clocks to ripple through, so the outputs settle faster.


In the schematic above, the ‘ counters increment the address on the rising edge of the clock, while the ‘ d-flop captures the data datasheet the last address before it changes.


This would work – with the 12ns SRAM access time, still way under the 40ns cycle time. Now, I need 5 ICs to make the counter – if it’s even fast enough.

In the store-each-dot-period-as-a-byte plan, this is trivial – I have full and easy control of all the singals on on a per-dot basis.

I’ll have to give that one some thought. I’m already bummed about the color thing That should relax some timing as your MSB are no longer rely on the propagation from the lower bits. Maybe I’m doing this wrong? The dot clock is I started with the VHC part this time: