SAB88C166 Datasheet, PDF (35/58 Pages) Siemens Semiconductor Group – 16-Bit CMOS Single-Chip Microcontrollers with/without oscillator prescaler with 32 KByte Flash EPROM

SAB 88C166(W)
AC Characteristics
The specification of the timings depends on the CPU clock signal that is used in the respective
device. In this regard the specification for the SAB 88C166 and the SAB 88C166W are different.
While the SAB 88C166W directly uses the clock signal fed to XTAL1 and therefore has to take into
account the duty cycle variation of this signal, the SAB 88C166 derives its CPU clock from the
XTAL1 signal via a 2:1 prescaler and therefore is independant from these variations.
For these reasons the following pages provide the timing specifications for SAB 88C166 and for
SAB 88C166W separately (where applicable).
AC Characteristics
External Clock Drive XTAL1 for the SAB 88C166
V_CC = 5 V ± 10 %; V_SS = 0 V
T_A = 0 to +70 ˚C
for SAB 88C166-5M
Parameter
Oscillator period
High time
Low time
Rise time
Fall time
Symbol
Max. CPU Clock
= 20 MHz
Variable CPU Clock Unit
1/2TCL = 1 to 20 MHz
min.
max.
min.
max.
TCLSR 25
25
25
500
ns
t₁SR
6
–
6
–
ns
t₂SR
6
–
6
–
ns
t₃SR
–
5
–
5
ns
t₄SR
–
5
–
5
ns
Figure 15
External Clock Drive XTAL1
Semiconductor Group
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