Mixing XC9500 and XC9500XL, also small qty suppliers

fill

Mixing up 95 and 95xl ? That should work fine, but you have to consider the following:

- No interconnect level problems due to the 5V-tolerance of the 95xl.

- However the xl outputs drive to 3,3V only, 5V can be obtained by pullups only if outputs are tristated. Ignore that for 95/95xl interconnections or if TTL or HCT logic is driven.

- 95 CPLDs have higher I/O sink current at 5V I/O's (24mA), 95XL have 8mA only. Source current of 4mA is the same in both families (95 at 5V).

- 95XL is faster and cheaper, but (same as 95) has no input registers, so you must live with high setup times tsu. Consider connecting two 95216-20 together, the maximum clock frequency of synchronious interconnections can be 50MHz only. (Tsu+Tco=10+10ns). A 95216-20 and a 9572xl-10 can work up to 60,6MHz (Tco+Tsu=10+6.5ns), a little bit faster.

- Coolrunner and CoolRunner-II have input registers, but less logic ressources.

- 95/95xl JTAG chain can be 3,3V or 5V, see Xilinx Answer record #7270

At the German distri

95288XL in TQ144 and PQ208 can be ordered in small quantities:

MIKE

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www.oho-elektronik.de
OHO-Elektronik
Michael Randelzhofer
FPGA und CPLD Mini Module
Klein aber oho !

[snip]

Hmm, I might try fitting the logic into a Coolrunner in a few minutes. I've just eliminated three registers that should not have existed and got the logic down to 218 macrocells. Only two more MCs to optimize out, then I can (hopefully) get it to fit in a single XC95216. Failing that, I'll put the state machine logic in the 216 and move the vector output circuitry into a XC95144XL.

I just need to figure out if a 95*XL can communicate with 5V CMOS logic - I need to add some more glue logic to interface the vector generator to the system bus of a CMOS 6502 CPU. It seems bus buffers may be necessary.. thankfully the 6502 has a R/!W output, which makes buffering the data bus nice and easy (only need a 244 bus transceiver).

I'm also toying with the idea of building a Gameboy-based DSO or logic analyser - another device with a 5V CMOS CPU (a Z80 this time)...

That's a point - I completely forgot about the JTAG chain. Thanks for the link...

That would be great, were it not for this: >> We do not deliver to private end-users

So the search resumes :(

Thanks.

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Which 5V CMOS logic? If it is HCT then 3.3 volts from 95XL is a high level.

65(S)C02 should work at TTL levels. Only the clock input "needs" voltage swing up to full 5 volts. This is also true for NMOS 6502.

I

The 95*/95*xl mixture makes especially sense where 95* communicates with 5V CMOS or sinks higher currents, and 95xl cares for logic density and speed at noticeable lower prices.

Using 95*xl only with levelshifters for 5V CMOS and a 3,3V LDO is probably the cheapest solution.

CoolRunner XPLA3 devices have the same limits in driving 5V CMOS as 95*xl.

MIKE

--
www.oho-elektronik.de
OHO-Elektronik
Michael Randelzhofer
FPGA und CPLD Mini Module
Klein aber oho !

No idea at all - that's half the fun of designing hardware for a Gameboy, no voltage specs on the CPU, just a rather vague "it's a CMOS Z80 clone with an onboard LCD controller and a few instruction set tweaks"...

That's good to know.. I'll check the datasheet in a sec - the chip I'm using is a WDC W65C02SP.

Later.

--
Phil.                              | Acorn RiscPC600 SA220 64MB+6GB 100baseT
philpem@philpem.me.uk              | Athlon64 3200+ A8VDeluxe R2 512MB+100GB
http://www.philpem.me.uk/          | Panasonic CF-25 Mk.2 Toughbook
No software patents!           /  
... BNFL : Buy No Fish Locally

As I think everyone else has said TTL levels between the devices should work ok. The 9500XL parts are 5V tolerant so you can drive them with a 5V signal source.

You can get some of these CPLDs from Farnell in the UK with duty issues and they usually take credit cards. Official distributor is Silica in the UK.

John Adair Enterpoint Ltd. - Home of Raggedstone1. The low cost Spartan3 Development Board.

That's good to know. I'll have to see if I can get a 95144XL to communicate with a Gameboy CPU at some point. I know those things can handle 5V logic levels, but I'm not sure about 3.3V, and there's basically no documentation on that side of things. Well, not without much NDA signing anyway.

What do you mean by "duty issues"? I've tried Silica - they're not willing to supply anyone without company registration documents. Shame Memec aren't distributing Xilinx kit anymore - they were pretty good about supplying small quantities of parts.

Thanks.

--
Phil.                              | Acorn RiscPC600 SA220 64MB+6GB 100baseT
philpem@philpem.me.uk              | Athlon64 3200+ A8VDeluxe R2 512MB+100GB
http://www.philpem.me.uk/          | Panasonic CF-25 Mk.2 Toughbook
No software patents!           /  
A seminar on time travel will be held two weeks ago.