User Manual
476
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
General Purpose Timer Units (GPT12)
16.4.5
GPT2 Register CAPREL Operating Modes
The Capture/Reload register CAPREL can be used to capture the contents of timer T5, or to reload timer T6. A
special mode facilitates the use of register CAPREL for both functions at the same time. This mode allows
frequency multiplication. The capture function is triggered by CAPIN, by T3IN and T3EUD, or by read GPT1
timers. The reload function is triggered by an overflow or underflow of timer T6.
In addition to the capture function, the capture trigger signal can also be used to clear the contents of timers
T5 and T6 individually.
The functions of register CAPREL are controlled via several bit(field)s in the timer control registers T5CON and
T6CON.
Capture/Reload Register CAPREL in Capture Mode
Capture mode for register CAPREL is selected by setting bit T5SC in control register T5CON (set bitfield CI in
register T5CON to a non-zero value to select a trigger signal). In capture mode, the contents of the auxiliary
timer T5 are latched into register CAPREL in response to a signal transition at the selected external input
pin(s). Bit CT3 selects the external input line CAPIN or the input lines T3IN and/or T3EUD of GPT1 timer T3 as
the source for a capture trigger. Either a positive, a negative, or both a positive and a negative transition at line
CAPIN can be selected to trigger the capture function, or transitions on input T3IN or input T3EUD or both
inputs, T3IN and T3EUD. The active edge is controlled by bitfield CI in register T5CON.
summarizes
these options.
Table 255 CAPREL Register Input Edge Selection
CT3
CI
Triggering Signal/Edge for Capture Mode
X
00
B
None. Capture Mode is disabled.
0
01
B
Positive transition (rising edge) on CAPIN.
1)
1) Rising edge must be selected if capturing is triggered by the internal GPT1 read signals (see register PISEL and
“Combined Capture Modes” on Page 480
).
0
10
B
Negative transition (falling edge) on CAPIN.
0
11
B
Any transition (rising or falling edge) on CAPIN.
1
01
B
Any transition (rising or falling edge) on T3IN.
1
10
B
Any transition (rising or falling edge) on T3EUD.
1
11
B
Any transition (rising or falling edge) on T3IN or T3EUD.