UPD77015GC NEC, UPD77015GC Datasheet - Page 43

• Manufacturer Part Number: UPD77015GC
• Description: 16 bits/ Fixed-point Digital Signal Processor
• Manufacturer: NEC

Serial Interface
Required Timing Condition
Switching Characteristics
Notes for Serial Clock
induced voltage, etc.). Spurious signals can cause malfunction of the device. Special care for the serial clock
design should be taken. Careful grounding, decoupling and short wiring of SCK1 and SCK2 are recommended.
Intersection of SCK1 and SCK2 with other serial interface lines or close wiring to lines carrying high frequency
signals or large changing currents should be avoided.
SCK input cycle time
SCK input high/low level width
SCK input rise/fall time
SOEN recovery time
SOEN hold time
SIEN recovery time
SIEN hold time
SI setup time
SI hold time
SORQ output delay time
SORQ hold time
SO valid time
SO hold time
SIAK output delay time
SIAK hold time
Serial clock inputs SCK1 and SCK2 are sensitive to any kind of interfering signals (noise on power supply,
It considers for the serial clock to make a waveform stable especially about the rising and falling.
Example 1. good example
Straight rising form and falling
form
Parameters
Parameters
Example 2. no good example
It doesn’t bound. It doesn’t make
noise one above another.
Symbol
Symbol
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
cSC
wSC
rfSC
recSOE
hSOE
recSIE
hSIE
suSI
hSI
dSOR
hSOR
vSO
hSO
dSIA
hSIA
Conditions
Conditions
MIN.
MIN.
2t
25
20
20
20
0
0
0
0
0
0
cC
PD77015, 77017, 77018
Example 3. no good example
It doesn’t make a stair stepping.
TYP.
TYP.
MAX.
MAX.
20
30
30
30
Unit
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
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