SAF-C515-L24M SIEMENS [Siemens Semiconductor Group], SAF-C515-L24M Datasheet - Page 25

• Manufacturer Part Number: SAF-C515-L24M
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [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 the “timer” function (C/T = ‘0’) the register is incremented every machine cycle. Therefore the
count rate is
In the “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 9 illustrates the
input clock logic.
Figure 9
Timer/Counter 0 and 1 Input Clock Logic
Semiconductor Group
Description
8-bit timer/counter with a
divide-by-32 prescaler
16-bit timer/counter
8-bit timer/counter with
8-bit autoreload
Timer/counter 0 used as one
8-bit timer/counter and one
8-bit timer
Timer 1 stops
f
OSC
P3.4/T0
P3.5/T1
max
P3.2/INT0
P3.3/INT1
/12.
f
OSC
/24
TR 0/1
TCON
TMOD
Gate
f
OSC
f
OSC
=1
/24. External inputs INT0 and INT1 (P3.2, P3.3) can be
M1
÷
0
1
1
1
12
TMOD
25
_
<
1
M0
0
1
0
1
0
1
TMOD
C/T
MCS01768
&
f
OSC
internal
f
OSC
/12x32
/12
Control
Input Clock
external (max)
f
Timer 0/1
Input Clock
OSC
f
OSC
/12
f
OSC
/24x32
1997-08-01
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C515