ADP315PC87570 National Semiconductor, ADP315PC87570 Datasheet - Page 113

• Manufacturer Part Number: ADP315PC87570
• Description: Keyboard and Power Management Controller
• Manufacturer: National Semiconductor

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14.4.2 Timer Interrupts
The MFT16 contains a total of four interrupt sources which
are mapped to two different system interrupts. All sources
have a pending flag associated with them, and can be en-
abled or disabled under software control. The pending flags
are TXPND, where n is the module and X is a letter from A
to D. An interrupt enable flag, TXIEN, is associated with
each interrupt pending flag. The interrupt source A, B and C
can generate a timer interrupt I, while the interrupt source D
can generate a timer interrupt II. Note that not all interrupt
sources are available in all modes. Table 14-2 shows which
events can trigger an interrupt in which mode of operation:
Timer
Timer
T
T
I/O
Int. II
Sys.
Int. I
Int.
A
B
T
T
T
T
T
T
T
T
Interrupt
Pending
T
T
T
T
T
T
AEN=0
BEN=X
AEN=1
BEN=X
AEN=X
BEN=0
AEN=X
BEN=1
Flag
CPND
DPND
AEN
BEN
APND
BPND
Toggle Output on un-
T
T
PWM and Counter
PWM and Counter
Ext. Event or Pulse
Ext. Event or Pulse
T
derflow of
Accumulate Input
Accumulate Input
CNT1 reload from
CNT1 reload from
CNT2 underflow
No Output
Mode 1
Mode 1
T
T
N/A
CRA
CRB
T
CNT1
Multi-Function 16-Bit Timer (MFT16)
Table 14-3. MFT16 I/O Functions
Table 14-2. MFT16 Interrupts
Input Capture on
Input capture on
Dual Input Capture
Capture
Capture
Capture
Capture
Dual Input Capture
T
T
T
T
CNT1 underflow
CNT2 underflow
CRA and preset
CRB and preset
transition
transition
Mode 2
Mode 2
T
T
T
T
113
CNT1
CNT1
T
T
T
T
CRA
CRB
CNT1 into
CNT1 into
CNT1 into
CNT1 into
14.4.3 Timer I/O Functions
There are two I/O pins associated with each MFT, TA and
TB. The functionality of TA and TB depends on the mode of
operation, and the value of the TAEN and TBEN bits. Table
14-3 shows the function of TA and TB versus the selected
mode of operation. Note that if TA functions as a PWM out-
put, the initial and present value of TA is defined by TAOUT.
For example, if you want to start with TA high, TAOUT must
be set (1) prior to enabling the timer clock.
T
T
A
B
Toggle Output on un-
T
T
Dual Independent
Ext. Event or Pulse
Ext. Event or Pulse
Dual Independent
derflow of
CNT1 reload from
CNT2 reload from
No Output toggle
Accumulate Input
Accumulate Input
Mode 3
Mode 3
T
T
Timer
Timer
N/A
N/A
CRA
CRB
T
CNT1
Input Capture on
Toggle Output on un-
T
Input Capture and
Capture
Capture
Input Capture and
T
derflow of
T
CNT1 reload from
No Output toggle
CNT2 underflow
CRB and preset
transition
Mode 4
Mode 4
T
T
Timer
T
Timer
N/A
CNT2
CRA
T
T
CRB
CNT2 into
CNT2 into
T
CNT1
T
B