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EP2SGX60CF780C4N Datasheet, PDF (143/316 Pages) Altera Corporation – Support for numerous single-ended and differential I/O standards | |||
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Stratix II GX Architecture
Table 2â36 contains board design recommendations to ensure that nCEO
can successfully drive nCE for all power supply combinations.
Table 2â36. Board Design Recommendations for nCEO and nCE Input Buffer Power
nCE Input Buffer Power in
Stratix II GX nCEO VCCIO Voltage Level in I/O Bank 7
I/O Bank 3
VC C I O = 3.3 V VC C I O = 2.5 V VC C I O = 1.8 V VC C I O = 1.5 V VC C I O = 1.2 V
VCCSEL high
(VC C I O Bank 3 = 1.5 V)
VCCSEL high
(VC C I O Bank 3 = 1.8 V)
v(1), (2)
v (1), (2)
v (3), (4)
v (3), (4)
v (5)
v
v
v
v
Level shifter
required
VCCSEL low (nCE powered
v
by VC C P D = 3.3 V)
v (4)
v (6)
Level shifter Level shifter
required
required
Notes to Table 2â36:
(1) Input buffer is 3.3-V tolerant.
(2) The nCEO output buffer meets VO H (MIN) = 2.4 V.
(3) Input buffer is 2.5-V tolerant.
(4) The nCEO output buffer meets VOH (MIN) = 2.0 V.
(5) Input buffer is 1.8-V tolerant.
(6) An external 250-Ω pull-up resistor is not required, but recommended if signal levels on the board are not optimal.
For JTAG chains, the TDO pin of the first device drives the TDI pin of the
second device in the chain. The VCCSEL input on the JTAG input I/O cells
(TCK, TMS, TDI, and TRST) is internally hardwired to GND selecting the
3.3-V/2.5-V input buffer powered by VCCPD. The ideal case is to have the
VCCIO of the TDO bank from the first device match the VCCSEL settings for
TDI on the second device, but that may not be possible depending on the
application. Table 2â37 contains board design recommendations to
ensure proper JTAG chain operation.
Table 2â37. Supported TDO/TDI Voltage Combinations (Part 1 of 2)
Device
TDI Input
Buffer Power
Stratix II GX Always
VC C P D (3.3 V)
Stratix II GX TDO VC C I O Voltage Level in I/O Bank 4
VC C I O = 3.3 V
v (1)
VC C I O = 2.5 V
v (2)
VC C I O = 1.8 V VC C I O = 1.5 V VC C I O = 1.2 V
v (3)
Level shifter Level shifter
required
required
Altera Corporation
October 2007
2â135
Stratix II GX Device Handbook, Volume 1
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