pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 211

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

Revision 1.07
Embedded Controller Modules
Interrupt Structure
The ACM Interrupt is generated to the core if an event from Table 26 becomes active. Since the events are enabled in dif-
ferent ACM operation modes, only one event may occur at a time.
When an event flag and its related mask bit are set (enabled), the ACM Interrupt request is asserted. This is indicated by
a high level of the ACM Interrupt signal.
The software must reset the event flag (or its mask bit) to de-assert the ACM Interrupt request.
All the event flags (EOMEV, EOCEV and OVUNTHEV) are cleared by writing 1 to START in ACMCTS register.
The ACM Interrupt is routed both to the ICU and to the MIWU as an ACMI signal (see Section 4.3 on page 98 and Section 4.4
on page 105).
ACM Operating Sequences
The ACM has three operating modes:
After the ACM is properly initialized, one of these modes should be used. The operation sequences are as follows:
Voltage Level Burst Mode (ACMMOD = 01
1. Start a new burst of eight voltage measurements by setting START bit in ACMCTS register to 1.
2. When End-of-Voltage level measurement burst is reached, software can detect the event by waiting for EOMEV in
3. Read measured voltage level - Input 0, for channel 0, by reading VOLTLVL in VOLDAT0 register.
4. Read measured voltage level - Input 1, for channel 1, by reading VOLTLVL in VOLDAT1 register.
5. Read measured voltage level - Input 2, for channel 2, by reading VOLTLVL in VOLDAT2 register.
6. Read measured voltage level - Input 3, for channel 3, by reading VOLTLVL in VOLDAT3 register.
7. Read measured voltage level - Input 4, for channel 4, by reading VOLTLVL in VOLDAT4 register.
8. Read measured voltage level - Input 5, for channel 5, by reading VOLTLVL in VOLDAT5 register.
9. Read measured voltage level - Input 6, for channel 6, by reading VOLTLVL in VOLDAT6 register.
10. Read measured voltage level - Input 7, for channel 7, by reading VOLTLVL in VOLDAT7 register.
11. Clear the event flag (release the ACM interrupt if enabled) by writing 1 to EOMEV in ACMCTS register.
Threshold Comparison Burst Mode -(ACMMOD = 10
1. Set the desired threshold value in bits THRSHD(5-0) in THRDAT register.
2. Start a new burst of threshold comparison by setting START in ACMCTS register to 1.
3. When End-of-Threshold comparison burst is reached, software can detect the event by waiting for EOCEV in ACMCTS
4. Read comparison result for inputs 0 to 7 by reading bits CMPIN(0-7) in CMPRES register.
5. Clear the event flag by writing 1 to EOCEV in ACMCTS register.
EOMEV
OVUNTHEV ACMCTS
Event Flag
Voltage Level Burst mode
Threshold Comparison Burst mode
Low-Power Threshold Comparison mode
ACMCTS register to be set to 1.
register to be set to 1.
ACMCTS
Mnemonic
Register
INTEMEN
INTOUEN
Mask Bit
Table 26. ACM Interrupt Structure
2
ACMCNF
ACMCNF
(Continued)
)
Mnemonic
Register
2
)
End-of-Measurement event and associated interrupt enable
Over/Under Threshold event and associated interrupt enable
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Description
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