初學者一問......有關EPM7128S......VCCINT & VCCIO的問題

jimcooper

請問一下VCCINT & VCCIO還有其對應的GND 這些腳位是做甚麼用的啊??
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我已經看我DATASHEET上對這方面的說明,但感覺還是有點不清楚
2 ^7 _1 H! v5 V# {; Y( ]2 ?感覺上VCCINT & VCCIO好像只需要各接一隻腳就可以了,其他相同名稱的腳位都是相通的.....
我的想法正確嗎??

如果布正確的話....
能麻煩各位幫我做個詳細的解說嗎??
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先說聲謝謝~

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----------以下是DATASHEET針對VCCIO & VCCINT所做的說明------------
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0 A1 Z9 A( ^  vMultiVolt I/O Interface
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3 U4 n6 \3 h. G! `4 EMAX 7000 devices—except 44-pin devices—support the MultiVolt I/O
interface feature, which allows MAX 7000 devices to interface with
  w7 c( u# ~' J+ q! bsystems that have differing supply voltages. The 5.0-V devices in all
packages can be set for 3.3-V or 5.0-V I/O pin operation. These devices
have one set of VCC pins for internal operation and input buffers
(VCCINT), and another set for I/O output drivers (VCCIO).
The VCCINT pins must always be connected to a 5.0-V power supply.
" k4 o/ C" I& p* ]8 ?& t2 O" P9 hWith a 5.0-V VCCINT level, input voltage thresholds are at TTL levels, and
are therefore compatible with both 3.3-V and 5.0-V inputs.
3 c9 t1 v7 o: U$ @The VCCIO pins can be connected to either a 3.3-V or a 5.0-V power
supply, depending on the output requirements. When the VCCIO pins are
connected to a 5.0-V supply, the output levels are compatible with 5.0-V
( z# w+ C1 c1 h+ J- a5 C  x; jsystems. When VCCIO is connected to a 3.3-V supply, the output high is
. h% V2 M9 V% C3.3 V and is therefore compatible with 3.3-V or 5.0-V systems. Devices
operating with VCCIO levels lower than 4.75 V incur a nominally greater
( n/ Q) Y) ^7 l3 b5 s  stiming delay of tOD2 instead of tOD1.
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, l5 ]! s: Q% h) C7 W& ][ 本帖最後由 jimcooper 於 2008-11-9 04:21 PM 編輯 ]