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請問一下VCCINT & VCCIO還有其對應的GND 這些腳位是做甚麼用的啊??6 ?9 Q( q6 o" V# o/ o6 ~; p
# V/ v: [( S% U我已經看我DATASHEET上對這方面的說明,但感覺還是有點不清楚8 A. d0 D$ B3 [. L
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.....
8 ?, x/ _$ j+ X% b我的想法正確嗎??
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如果布正確的話....% W7 s9 V7 u. _- b6 ^
能麻煩各位幫我做個詳細的解說嗎??
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先說聲謝謝~# m, z& C! L* r- F$ |; p4 G- U
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----------以下是DATASHEET針對VCCIO & VCCINT所做的說明------------) N. M6 g3 P+ L* M/ H
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MultiVolt I/O Interface
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MAX 7000 devices—except 44-pin devices—support the MultiVolt I/O/ o$ c% L5 w+ d; `& f9 M" `
interface feature, which allows MAX 7000 devices to interface with) h% T$ ?, R0 Y( T
systems that have differing supply voltages. The 5.0-V devices in all
* V% W" m( Z1 v1 I) x3 i) dpackages can be set for 3.3-V or 5.0-V I/O pin operation. These devices9 ^& [% D/ ^% ~0 L' j
have one set of VCC pins for internal operation and input buffers
' g0 `7 Z2 ^ C5 g" A' ~( X( }(VCCINT), and another set for I/O output drivers (VCCIO).
; B* p& G* G( xThe VCCINT pins must always be connected to a 5.0-V power supply.
* G; n( o7 O! c4 p0 P9 N! F% uWith a 5.0-V VCCINT level, input voltage thresholds are at TTL levels, and8 `, b+ S+ s0 h' c
are therefore compatible with both 3.3-V and 5.0-V inputs.2 N8 s' Y- }( r3 I5 X0 c
The VCCIO pins can be connected to either a 3.3-V or a 5.0-V power
, _8 s* N" j' X! L; jsupply, depending on the output requirements. When the VCCIO pins are% f# z; f6 }+ f6 }* r. L" j
connected to a 5.0-V supply, the output levels are compatible with 5.0-V
; l6 O0 S9 ~& @; b/ u# u* k5 Z* osystems. When VCCIO is connected to a 3.3-V supply, the output high is$ G* m3 }8 o: m' T
3.3 V and is therefore compatible with 3.3-V or 5.0-V systems. Devices% G6 V. _5 p& p2 [4 T, g0 Y2 b
operating with VCCIO levels lower than 4.75 V incur a nominally greater. x2 {6 ~$ ^; p- _" A
timing delay of tOD2 instead of tOD1.
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% x+ d. n0 E) L* _- \! N4 G[ 本帖最後由 jimcooper 於 2008-11-9 04:21 PM 編輯 ] |
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