NXP Semiconductors LPC822M101JDH20, User Manual, Page: 153 / 487

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User manual Rev. 1.2 — 5 October 2016 153 of 487
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Chapter 10: LPC82x Pin interrupts/pattern match engine
10.7.2 Pattern Match engine example
Suppose the desired boolean pattern to be matched is:
(IN1) + (IN1 * IN2) + (~IN2 * ~IN3 * IN6fe) + (IN5 * IN7ev)
with:
IN6fe = (sticky) falling-edge on input 6
IN7ev = (non-sticky) event (rising or falling edge) on input 7
Each individual term in the expression shown above is controlled by one bit-slice. To
specify this expression, program the pattern match bit slice source and configuration
register fields as follows:
•
PMSRC register ( Table 139 ):
– Since bit slice 5 will be used to detect a sticky event on input 6, you can write a 1 to
the SRC5 bits to clear any pre-existing edge detects on bit slice 5.
– SRC0: 001 - select input 1 for bit slice 0
– SRC1: 001 - select input 1 for bit slice 1
– SRC2: 010 - select input 2 for bit slice 2
– SRC3: 010 - select input 2 for bit slice 3
– SRC4: 011 - select input 3 for bit slice 4
– SRC5: 110 - select input 6 for bit slice 5
– SRC6: 101 - select input 5 for bit slice 6
– SRC7: 111 - select input 7 for bit slice 7
•
PMCFG register ( Table 140 ):
– PROD_ENDPTS0 = 1
– PROD_ENDPTS02 = 1
– PROD_ENDPTS5 = 1
– All other slices are not product term endpoints and their PROD_ENDPTS bits are
0. Slice 7 is always a product term endpoint and does not have a register bit
associated with it.
– = 0100101 - bit slices 0, 2, 5, and 7 are product-term endpoints. (Bit
slice 7 is an endpoint by default - no associated register bit).
– CFG0: 000 - high level on the selected input (input 1) for bit slice 0
– CFG1: 000 - high level on the selected input (input 1) for bit slice 1
– CFG2: 000 - high level on the selected input (input 2) for bit slice 2
– CFG3: 101 - low level on the selected input (input 2) for bit slice 3
– CFG4: 101 - low level on the selected input (input 3) for bit slice 4
– CFG5: 010 - (sticky) falling edge on the selected input (input 6) for bit slice 5
– CFG6: 000 - high level on the selected input (input 5) for bit slice 6
– CFG7: 111 - event (any edge, non-sticky) on the selected input (input 7) for bit
slice 7
•
PMCTRL register ( Table 138 ):