VCCIO EPM7128SLC84-15 and 5 Volt outputs: HELP!

[Altera_Forum]

I'm using a MAX EPM7128SLC84-15 and need 5V logic outputs. So, the CPLD is wired with all VCC=5V and all the VCCIO = 5V too. Yet the outputs show 3.3V on the 'scope. I believed the Data Sheet pages 2, 6 and 20. What am I doing wrong, please? 

 Yes, I read a 100+ posts on the Wiki and searched and searched - but no luck ;-)  Best wishes - Chosulman.

[Altera_Forum]

According to the MAX7000 datasheet (chapter MultiVolt-I/O Interface), external pull-up resistors are required to guarantee 5V CMOS compatible output levels. Without it, a Voh of about 3,8V is achieved with 5V VCCIO.

[Altera_Forum]

@FvM: Thank you! Can you point to the document for this, please; I'm looking at the MAX7000 Programmable Logic Device Family data sheet Sept 2005, ver 6.7 page 20 where there is no mention of external pull-ups ... 

 Admittedly, I did wonder, and will try it. More later.

[Altera_Forum]

@FvM: Later ... 

 Yes, that did it. Many thanks. The data sheet (pages 20/21) is confusing on this point. My measurements suggest that when in VCCIO = 5V mode, the outputs are actively pulled down to 0V and actively pulled up to 3.3V. Above 3.3V the outputs are open_drain. So your pull up helps you on upwards to 5V, albeit slowly. Curious design ...  BTW, the hardware is located in Bochum. Small world! Email me if you're interested in a visit (Sternwarte). [Can't email you - too few posts].

[Altera_Forum]

Yes, the external pull-up operation is rather slow, unless low, power consuming resistors are used. Are you sure, that you actually need high levels above 3.5V?

[Altera_Forum]

Unfortunately yes. The signals interface with 5V CMOS logic and some signals needed the extra energy to drive it. 

 Thanks again for your help - and the visit offer's genuine!