IDT49C465 Ver la hoja de datos (PDF) - Integrated Device Technology
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IDT49C465 Datasheet PDF : 38 Pages
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IDT49C465/A
32-BIT FLOW-THRU ERROR DETECTION AND CORRECTION UNIT
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DEFINITIONS OF TERMS:
D0 – D31 = System Data and/or Memory Data Inputs
CBI0 – CBI7 = Checkbit Inputs
PCBI0 – PCBI7 = Partial Checkbit Inputs
FS0 – FS7 = Final Internal Syndrome bits
FUNCTIONAL EQUATIONS:
The equations below describe the terms used in the
IDT49C465 to determine the values of the partial checkbits,
checkbits, partial syndromes and final internal syndromes.
NOTE: All “⊕” symbols below represent the “EXCLUSIVE-
OR” function.
PA = D0 ⊕ D1 ⊕ D2 ⊕ D4 ⊕ D6 ⊕ D8 ⊕ D10 ⊕ D12 ⊕ D16 ⊕ D17
⊕ D18 ⊕ D20 ⊕ D22 ⊕ D24 ⊕ D26 ⊕ D28
PB = D0 ⊕ D3 ⊕ D4 ⊕ D7 ⊕ D9 ⊕ D10 ⊕ D13 ⊕ D15 ⊕ D16 ⊕ D19
⊕ D20 ⊕ D23 ⊕ D25 ⊕ D26 ⊕ D29 ⊕ D31
PC = D0 ⊕ D1 ⊕ D5 ⊕ D6 ⊕ D7 ⊕ D11 ⊕ D12 ⊕ D13 ⊕ D16 ⊕ D17
⊕ D21 ⊕ D22 ⊕ D23 ⊕ D27 ⊕ D28 ⊕ D29
PD = D2 ⊕ D3 ⊕ D4 ⊕ D5 ⊕ D6 ⊕ D7 ⊕ D14 ⊕ D15 ⊕ D18 ⊕ D19
⊕ D20 ⊕ D21 ⊕ D22 ⊕ D23 ⊕ D30 ⊕ D31
PE = D8 ⊕ D9 ⊕ D10 ⊕ D11 ⊕ D12 ⊕ D13 ⊕ D14 ⊕ D15 ⊕ D24
⊕ D25 ⊕ D26 ⊕ D27 ⊕ D28 ⊕ D29 ⊕ D30 ⊕ D31
PF = D0 ⊕ D1 ⊕ D2 ⊕ D3 ⊕ D4 ⊕ D5 ⊕ D6 ⊕ D7 ⊕ D24 ⊕ D25
⊕ D26 ⊕ D27 ⊕ D28 ⊕ D29 ⊕ D30 ⊕ D31
PG = D8 ⊕ D9 ⊕ D10 ⊕ D11 ⊕ D12 ⊕ D13 ⊕ D14 ⊕ D15 ⊕ D16
⊕ D17 ⊕ D18 ⊕ D19 ⊕ D20 ⊕ D21 ⊕ D22 ⊕ D23
PH0 = D0 ⊕ D4 ⊕ D6 ⊕ D7 ⊕ D8 ⊕ D9 ⊕ D11 ⊕ D14 ⊕ D17 ⊕ D18
⊕ D19 ⊕ D21 ⊕ D26 ⊕ D28 ⊕ D29 ⊕ D31
PH1 = D1 ⊕ D2 ⊕ D3 ⊕ D5 ⊕ D8 ⊕ D9 ⊕ D11 ⊕ D14 ⊕ D17 ⊕ D18
⊕ D19 ⊕ D21 ⊕ D24 ⊕ D25 ⊕ D27 ⊕ D30
PH2 = D0 ⊕ D4 ⊕ D6 ⊕ D7 ⊕ D10 ⊕ D12 ⊕ D13 ⊕ D15 ⊕ D16 ⊕
D20 ⊕ D22 ⊕ D23 ⊕ D26 ⊕ D28 ⊕ D29 ⊕ D31
CMOS TESTING CONSIDERATIONS
Special test board considerations must be taken into
account when applying high-speed CMOS products to the
automatic test environment. Large output currents are being
switched in very short periods and proper testing demands
that test set-ups have minimized inductance and guaranteed
zero voltage grounds. The techniques listed below will assist
the user in obtaining accurate testing results:
1) All input pins should be connected to a voltage potential
during testing. If left floating, the device may oscillate,
causing improper device operation and possible latchup.
2) Placement and value of decoupling capacitors is critical.
Each physical set-up has different electrical
characteristics and it is recommended that various
decoupling capacitor sizes be experimented with.
Capacitors should be positioned using the minimum lead
lengths. They should also be distributed to decouple
power supply lines and be placed as close as possible to
the DUT power pins.
3) Device grounding is extremely critical for proper device
testing. The use of multi-layer performance boards with
radial decoupling between power and ground planes is
necessary. The ground plane must be sustained from the
performance board to the DUT interface board and wiring
unused interconnect pins to the ground plane is recom-
mended. Heavy gauge stranded wire should be used for
power wiring, with twisted pairs being recommended for
minimized inductance.
4) To guarantee data sheet compliance, the input thresholds
should be tested per input pin in a static environment. To
allow for testing and hardware-induced noise, IDT recom-
mends using VIL ≤ 0V and VIH ≥ 3V for AC tests.
11.7
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