[Milkymist-devel] Fwd: Re: Debug status of MM One initial test
adam at sharism.cc
Sun Jun 27 23:29:43 PDT 2010
About the VCCINT typical quescent current issue. Just got official
replies from Xilinx:
1. accourding ds162.pdf, Iccintq typical quescent current of
XC6S45-2 is 18mA. The current will rise up to 0.12A when only provide
the Vccint for XC6S45-2. Is there any document to talking about this?
or any answer to indicate this issue?
>> No document talking about this. What’s the purpose to provide Vccint only to Spartan-6? I cannot see any sense to do this.
2. accourding ds162.pdf, table 4 "Typical Quiescent Supply
Current", what this table measure condition?
the issue is, my customer try to measure the quiescent qurrent, but
the result are difference from ds162 table4.
is there any document to write it down?
I need document to make customer well know what the difference, and
make they to understand the result is acceptable
>> Testing condition: at nominal voltage, 25°C junction temperatures (Tj). Typical values are for blank configured devices with no output current loads, no active input pull-up resistors, all I/O pins are 3-state and floating.
This is stated in Note 1, 2 of Table 4, DS162:
Different quiescent values should be estimated with XPE:
Besides, if the customer is using an ES chip to test the quiescent
values, he should know:
3. the issue is: only proivde Vccint for S6, and the Iccint rise
up to 0.12A. at this condition, why s6 still work well??
>> FPGA cannot work if you only providing Vccint. Only after Vccint, Vccaux and Vcco2 receive their respective threshold will Spartan-6 begin to work.
>From above replies, seems they still have works on the maximum
quiescent current which will be specified at production release of the
Spartan-6 devices. Unfortunately we're exactly using ES version. Also
pls reference  I measured. From them, the M1 boards meet spec.
within 50ms ramp time.
On the future use of end-user side, this should not be happended like
we tried to measure 1.2V supply only.
So we can close this issue in this RC1 run. At most, next run we keep
an eye on monitoring their max. spec. at production version.
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