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370
User
’
s Manual U15017EJ2V0UD
CHAPTER 21 ELECTRICAL SPECIFICATIONS
(3) Serial operation (T
A
=
40 to +85
°
C, V
DD
= AV
DD
= 4.5 to 5.5 V, V
SS
= AV
SS
= 0 V)
(a) 3-wire serial I/O mode (SCKn: Internal clock output)
Parameter
Symbol
Conditions
MIN.
TYP.
MAX.
Unit
SCKn cycle time
t
KCY1
Fastest setting by CSIMn: f
XX
/8 (f
XX
= 12.5 MHz)
640
ns
SCKn low-level width t
KL1
t
KCY1
/2
50
270
ns
SCKn high-level
width
t
KH1
t
KCY1
/2
50
270
ns
SIn setup time
(to SCKn
↑
)
t
SIK1
70
ns
SIn hols time
(from SCKn
↑
)
t
KSI1
80
ns
Delay time from
SCKn
↓
to SOn
output
t
KSO1
80
ns
Remark
n = 0 or 1
(b) 3-wire serial I/O mode (SCKn: External clock input)
Parameter
Symbol
Conditions
MIN.
TYP.
MAX.
Unit
SCKn cycle time
t
KCY2
640
ns
SCKn low-level width t
KL2
t
KCY2
/2
50
270
ns
SCKn high-level
width
t
KH2
t
KCY2
/2
50
270
ns
SIn setup time
(to SCKn
↑
)
t
SIK2
70
ns
SIn hols time
(from SCKn
↑
)
t
KSI2
80
ns
Delay time from
SCKn
↓
to SOn
output
t
KSO2
80
ns
Remark
n = 0 or 1
Caution The SCK2 pin of serial interface 2 (SIO2) is an N-ch open drain pin. Therefore, if internal clock
output is selected, the clock output from the pin is not a waveform with 50% duty. The values
set to bit 1 (SCL21) and bit 0 (SCL20) of serial operation mode register 2 (CSIM2) are the possible
clocks assuming that a 10 k
pull-up resistor is connected with operation at f
XX
= 4.194 MHz. Even
if the clock set by the SCL21 and SCL20 bits of the CSIM2 register is selected, it may not operate
correctly in conditions other than above, and depending on the board wiring capacitance, etc.
Be sure to evaluate the operation before use.
(c) UART mode
Parameter
Symbol
Conditions
MIN.
TYP.
MAX.
Unit
ASCK0 cycle time
t
KCY3
417
ns
ASCK0 low-level width
t
KL3
208
ns
ASCK0 high-level
width
t
KH3
208
ns