User Manual
449
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
General Purpose Timer Units (GPT12)
Timer Concatenation
Using the toggle bit T3OTL as a clock source for an auxiliary timer in Counter Mode concatenates the core
timer T3 with the respective auxiliary timer. This concatenation forms either a 32-bit or a 33-bit timer/counter,
depending on which transition of T3OTL is selected to clock the auxiliary timer.
•
32-bit Timer/Counter:
If both a positive and a negative transition of T3OTL are used to clock the auxiliary
timer, this timer is clocked on every overflow/underflow of the core timer T3. Thus, the two timers form a
32-bit timer.
•
33-bit Timer/Counter:
If either a positive or a negative transition of T3OTL is selected to clock the auxiliary
timer, this timer is clocked on every second overflow/underflow of the core timer T3. This configuration
forms a 33-bit timer (16-bit core timer + T3OTL + 16-bit auxiliary timer).
As long as bit T3OTL is not modified by software, it represents the state of the internal toggle latch, and can
be regarded as part of the 33-bit timer.
The count directions of the two concatenated timers are not required to be the same. This offers a wide variety
of different configurations.
T3, which represents the low-order part of the concatenated timer, can operate in Timer Mode, Gated Timer
Mode or Counter Mode in this case.
Figure 97 Concatenation of Core Timer T3 and an Auxiliary Timer
For measuring longer time periods, the core timer T3 may be concatenated with an auxiliary timer (T2/T4). The
core timer contains the low part, and the auxiliary timer contains the high part of the extended timer value.
MCA05399
Toggle Latch
T3OUT
T3IRQ
Count
T3R
Core Timer T3
Operating
Mode
Control
BPS1
TxI
T3IN
f
GPT
Auxiliary
Timer Tx
TxI
0
1
MUX
TxI.2
TxIN
TxIRQ
Up/Down
Up/Down
Count
MUX
TxRC
TxR
T3R
0
1
x = 2, 4
Edge
Select