3
9
4
13
6
HET
Res.
Angle
increment
HET
counter
10
Compare
value
When the HET counter passes from 9 to 13, the equality compare can not
match the compare value 10. Consequently, the angle position is missed!
9 10 11 12 13 14 15 16
3
9
4
13
Angle
counter
HET
Res.
Angle
increment
HET
counter
6
CNT position in the loop
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Angle Functions
1011
SPNU563A–March 2018
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High-End Timer (N2HET) Module
When the engine speed increases, the angle count can increment by more than one in a NHET resolution
but the HWAG will continue to provide the angle increment value at every resolution..
The NHET can then implement its own angle counter (using a CNT instruction in angle mode) which will
be incremented once per resolution by the value given by the angle increment. For an example of an
angle count within the NHET with increments, see Figure 23-52.
Figure 23-52. Angle Count Within the NHET With Increments
23.3.2.4.2 NHET Operation on Angle Functions (ACMP, CNT)
23.3.2.4.2.1 State of the Art
Because the angle value can be increased by more than one, the compare value could be in-between the
old angle value and the new angle value of the NHET angle counter (where new angle value = old angle
value + angle increment). To perform an angle compare that ensures not to miss a compare value, the
NHET provides the ACMP instruction. For an example of a compare without ACMP instruction, see
Figure 23-53.
Figure 23-53. Compare Without ACMP Instruction
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