SAF-C502-2R20N Siemens Semiconductor Group, SAF-C502-2R20N Datasheet - Page 19

• Manufacturer Part Number: SAF-C502-2R20N
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: Siemens Semiconductor Group

Timer/Counter 0 and 1
Timer/Counter 0 and 1 can be used in four operating modes as listed in table 4:
Table 4
Timer/Counter 0 and 1 Operating Modes
Mode
0
1
2
3
In “timer” function (C/T = ‘0’) the register is incremented every machine cycle. Therefore the count
rate is
In “counter” function the register is incremented in response to a 1-to-0 transition at its
corresponding external input pin (P3.4/T0, P3.5/T1). Since it takes two machine cycles to detect a
falling edge the max. count rate is
programmed to function as a gate to facilitate pulse width measurements. Figure 2 illustrates the
input clock logic.
Figure 2
Timer/Counter 0 and 1 Input Clock Logic
Semiconductor Group
f
OSC
Description
8-bit timer/counter with a
divide-by-32 prescaler
16-bit timer/counter
8-bit timer/counter with
8-bit auto-reload
Timer/counter 0 used as one
8-bit timer/counter and one
8-bit timer
Timer 1 stops
/12.
f
OSC
/24. External inputs INT0 and INT1 (P3.2, P3.3) can be
Gate
X
X
X
X
18
C/T
X
X
X
X
TMOD
M1
0
0
1
1
M0
0
1
0
1
f
internal
OSC
f
f
f
OSC
OSC
OSC
/
12
/
/
/
12
12
12
Input Clock
32
external
f
OSC
(max)
f
f
f
OSC
OSC
OSC
/
24
/
/
/
24
24
24
C502
32