EM78P257
OTP ROM
* Data in the Minimum, Typical, Maximum(“ Min” ,“ Typ” ,” Max” ) column are based on characterization results
at 25℃. This data is for design guidance and is tested.
6.2 AC Electrical Characteristic
(Ta=0~70° C, VDD=5V± 5%, VSS=0V)
Symbol
Dclk
Parameter
Conditions
Min
45
100
Typ
50
Max
55
DC
DC
Unit
%
ns
Input CLK duty cycle
Instruction cycle time
(CLKS="0")
Crystal type
RC type
Tins
500
ns
Ttcc
Tdrh
TCC input period
Device reset hold time
(Tins+20)/N*
10.78
ns
ms
ns
ms
ms
ms
ms
ms
15.4
20.2
Ta = 25°C
Ta = 25°C
Ta = 25°C
Ta = 25°C
Trst
Twdt1*
Twdt2*
Tset
Thold
Tdelay
/RESET pulse width
Watchdog timer period
Watchdog timer period
Input pin setup time
Input pin hold time
2000
10.78
0.75
15.4
1.07
0
20
50
20.2
1.39
Output pin delay time
Cload=20pF
* Twdt1: The Option word (SUT) is used to define the oscillator Set-Up time. WDT timeout length is the
same as set-up time(18ms).
* Twdt2: The Option word (SUT) is used to define the oscillator Set-Up time. WDT timeout length is the
same as set-up time(1ms).
* These parameters are characterizes but not tested.
* Data in the Minimum, Typical, Maximum(“ Min” ,“Typ”,”Max”) column are based on characterization
results at 25℃. This data is for design guidance and is not tested.
* N= selected prescaler ratio.
* The duration of watch dog timer is determined by option code (bit5).
This specification is subject to change without prior notice.
73
07.27.2004 (V1.4)
ELAN [ ELAN MICROELECTRONICS CORP ]
