User’s Manual
C166S V1 SubSystem
General Purpose Timer Unit
User’s Manual
12-13
V 1.6, 2001-08
Figure 12-7
Block Diagram of Core Timer T3 in Incremental Interface Mode
Bitfield T3I in control register T3CON selects the triggering transitions (see
Table 12-5
).
The sequence of the transitions of the two input signals is evaluated and generates count
pulses as well as the direction signal. Depending on whether Rotation Detection Mode
(T3M=’110
B
’) or Edge Detection Mode (T3M=’111
B
’) is chosen, an interrupt request on
T3IRQ is generated. For Rotation Detection Mode, an interrupt is generated each time
the count direction of Timer T3 changes. For Edge Detection Mode, an interrupt is
generated each time a count action for Timer T3 occurs. Count direction, changes in the
count direction, and count requests are monitored by status bits T3RDIR, T3CHDIR, and
T3EDGE in register T3CON. T3 is modified automatically according to the speed and
direction of the incremental encoder. Therefore, the contents of Timer T3 always
represents the encoder’s current position.
Table 12-5
Core Timer T3 (Incremental Interface Mode) Input Edge Selection
T3I
Triggering Edge for Counter Increment/Decrement
0 0 0
None. Counter T3 stops.
0 0 1
Any transition (rising or falling edge) on T3IN.
0 1 0
Any transition (rising or falling edge) on T3EUD.
0 1 1
Any transition (rising or falling edge) on any T3 input (T3IN or T3EUD).
1 X X
Reserved. Do not use this combination
Edge
Select
Timer T3
XOR
MUX
T3EUD
T3UDE
MCB03998_b
T3l
T3IN
T3OTL
T3IRQ
Phase
Detect
T3R
T3IRQ
T3
Edge
T3UD
T3
CHDIR
0
1
Change
Detection
T3
RDIR
T3IRQ
T3M
Up/
Down
T3M
T3OE
T3OUT
MUX
0
1
1
Содержание C166S V1 SubSystem
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Страница 126: ...User s Manual C166S V1 SubSystem Central Processing Unit User s Manual 3 96 V 1 6 2001 08...
Страница 178: ...User s Manual C166S V1 SubSystem Memory Organization User s Manual 4 52 V 1 6 2001 08...
Страница 206: ...User s Manual C166S V1 SubSystem Instruction Set User s Manual 5 28 V 1 6 2001 08...
Страница 306: ...User s Manual C166S V1 SubSystem Detailed Instruction Set User s Manual 6 100 V 1 6 2001 08...
Страница 362: ...User s Manual C166S V1 SubSystem The External Bus Interface User s Manual 8 40 V 1 6 2001 08...
Страница 452: ...User s Manual C166S V1 SubSystem General Purpose Timer Unit User s Manual 12 44 V 1 6 2001 08...
Страница 454: ...User s Manual C166S V1 SubSystem Instruction Index User s Manual 13 2 V 1 6 2001 08...
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