
DocID13284 Rev 2
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UM0404
The general purpose timer units
Figure 76. GPT1 block diagram
9.1.1
GPT1 core timer T3
The core timer T3 is configured and controlled via its bit-addressable control register
T3CON.
T3CON (FF42h / A1h)
SFR
Reset Value: 0000h
2
n
n=3...10
2
n
n=3...10
2
n
n=3...10
T2EUD
T2IN
CPU Clock
CPU Clock
CPU Clock
T3EUD
T4IN
T3IN
T4EUD
T2
Mode
T3
Mode
T4
Mode
GPT1 Timer T2
GPT1 Timer T3
GPT1 Timer T4
T3OTL
Reload
Capture
U/D
U/D
Reload
Capture
Interrupt
Request
Interrupt
Request
Interrupt
Request
T3OUT
U/D
P5.15
P3.7
P3.6
P3.4
P3.5
P5.14
P3.3
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-
-
-
-
-
T3OT
L
T3OE
T3UD
E
T3UD T3R
T3M
T3I
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
Bit
Function
T3I
Timer 3 Input Selection
- Depends on the operating mode, see respective sections.
T3M
Timer 3 Mode Control
(Basic Operating Mode)
0 0 0:
Timer Mode
0 0 1:
Counter Mode
0 1 0:
Gated Timer with Gate active low
0 1 1:
Gated Timer with Gate active high
1 0 X:
Reserved (do not use this combination)
1 1 0:
Incremental interface mode
1 1 1:
Reserved (do not use this combination)
T3R
Timer 3 Run bit
: T3R = ‘0’: Timer / Counter 3 stops - T3R = ‘1’:
Timer / Counter 3 runs
T3UD
Timer 3 Up / Down Control
(1)