AS and JTAG access to cyclone II device

Question

Hello, I did a design that has both JTAG access and AS access to a single cyclone II device, and am looking to see if I did it correctly.

For the AS circuit, I just used the suggested circuit shown in figure 13-7 in the altera document:

http://www.altera.com/literature/hb/cyc2/cyc2_cii51013.pdf, except the msel pins are pulled low.

For the JTAG circuit I used the figure 13-22 of the same document.

Its just the same as the recommended circuitry, using 2 2x5 headers, except NCE is driven differently depending on which mode you are in. I used a SPDT switch to determine this mode.

When in one position (RUN or JTAG), it feeds a 0 to the NCE pin of the FPGA. If in the other position (PROG) it feeds PIN 6 of the AS header, which is also pulled-down through a 10k resistor.

Is this the correct way to have both JTAG and Active Serial access to the FPGA using a serial device? Also if I am using the byte blaster cable to do the AS programming, is it correct to use standard AS, or fast AS, as determined by the msel pins?

Thank you, any insight is very much appreciated!

altera_forum · Answer

Combination of AS and JTAG configuration schemes is described under "Combining JTAG & Active Serial Configuration Schemes". Basically it's an AS configuration circuit with additional JTAG header. No switch or similar element is required for it, because JTAG takes precedence over AS, you should however observe the comments about disabling configuration with a blank device.

For newer devices, e.g. Cyclone III, the a circuit for the combined scheme is shown in the device handbook.

It should be noted, that the AS flash can be also written through JTAG indirect programming for all Cyclone family FPGAs series, so the AS header isn't strictly required.

altera_forum · Answer

Thanks! Simplicity is always best!

altera_forum · Answer

Hello, Apologies for the delay in reply, but would you be able to point me in the direction of a document on how to "indirect" program the EPC flash via the using the JTAG port? I have searched the forums as well as google and have come up empty...

altera_forum · Answer

open File &gt; Convert Programming Files select .jic (JTAG indirect) as the output type select appropriate EPCS device click SOF data, then Add File to add your .sof click properties to optionally enable compression click Flash Loader then Add Device to select your target device click Generate open Tools &gt; QII Programmer click Auto Detect double click in File column of your FPGA device row select .jic file click the Program/Configure check box in the new EPCS device listed click Start

altera_forum · Answer

Thanks! Your brevity is very much appreciated.. I did find the indirect programming reference document right after I asked the question, but your cliff notes version is much better.. thanks again

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AS and JTAG access to cyclone II device

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