Siemens SAB 80515 Series User Manual page 66

Figure 7-19
Special Function Register TCON (Address 88 H )
8F H
88 H TF1
Bit
TR0
TF0
TR1
TF1
Each timer consists of two 8-bit registers (TH0 and TL0 for timer/counter 0, TH1 and TL1 for timer/
counter 1) which may be combined to one timer configuration depending on the mode that is
established. The functions of the timers are controlled by two special function registers TCON and
TMOD, shown in figures 7-19 and 7-20.
In the following descriptions the symbols TH0 and TL0 are used specify the high-byte and low-byte
of timer 0 (TH1 and TL1 for timer 1, respectively). The operating modes are described and shown
for timer 0. If not explicitly noted, this applies also to timer 1.
Semiconductor Group
8E H 8D H
TR1 TF0
These bits are not used in controlling timer/counter 0 and 1.
Function
Timer 0 run control bit.
Set/cleared by software to turn timer/counter 0 ON/OFF.
Timer 0 overflow flag. Set by hardware on timer/counter overflow.
Cleared by hardware when processor vectors to interrupt routine.
Timer 1 run control bit.
Set/cleared by software to turn timer/counter 1 ON/OFF.
Timer 1 overflow flag. Set by hardware on timer/counter overflow.
Cleared by hardware when processor vectors to interrupt routine.
On-Chip Peripheral Components
8C H 8B H 8A H
TR0 IE1 IT1
*
66
89 H 88 H
IE0 IT0 TCON