pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 140

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

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Embedded Controller Modules
Note that TnCNT2 can not operate in the Pulse Accumulate or External Event Counter modes since TBn input is used as a
capture input. Selecting either Pulse Accumulate mode or External Event Counter mode for TnCNT2 causes TnCNT2 to stop.
Note, however, that all available clock source modes may be selected for TnCNT1. Thus it is possible to use TnCNT1 to
determine the number of capture events on TBn or the elapsed time between capture events on TBn.
4.7.4
The MFT16 contains a total of four interrupt sources that are mapped to two different system interrupts. All sources have a
pending flag associated with them and can be enabled or disabled under software control. The pending flags are TnXPND,
where n is the module and X is a letter from A to D. An interrupt enable flag, TnXIEN, is associated with each interrupt pend-
ing flag. Interrupt sources A, B or C can generate a timer interrupt 1; interrupt source D can generate a timer interrupt 2.
Note that not all interrupt sources are available in all modes. Table 19 shows which events can trigger an interrupt in each
mode of operation:
Interrupt
System
Timer
Int. 1
Int. 2
Tier
Timer 1
Clock
Timer 2
Clock
Timer Interrupts
Interrupt
TnCPND
TnDPND
Pending
TnAPND
TnBPND
Flag
TnCNT1 reload from
TnCNT1 reload from
PWM and Counter
TnCNT2 underflow
Timer/Counter 1
Timer/Counter 2
Mode 1
TnCNT1
Figure 50. Mode 4, Input Capture and Timer
TnCRA
TnCRB
Capture B
Reload A
TnCRA
TnCRB
N/A
TnCNT2
Underflow
(Continued)
Table 19. MFT16 Interrupts
Input Capture on TBn
Input capture on TAn
Dual Input Capture
TnCNT1 underflow
TnCNT2 underflow
Preset
transition
transition
Mode 2
140
TBEN
TnCNT1 reload from
TnCNT2 reload from
Dual Independent
Mode 3
TnCRA
TnCRB
Timer
N/A
N/A
TBPND
TAPND
TDPND
TBIEN
TAIEN
TDIEN
TATEN
Input Capture on TBn
TnCNT1 reload from
Input Capture and
TnCNT2 underflow
Interrupt 1
Interrupt 1
transition
Interrupt 2
Mode 4
TnCRA
Timer
Timer
Timer
Timer
N/A
TAn
T
Revision 1.07
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