AS3911 Datasheet, PDF (115/149 Pages) ams AG – NFC Initiator / HF Reader IC

Application Information
Capacitance Measurement Configuration Register
Figure 110:
Capacitance Measurement Configuration Register
Address 3A_h: Capacitance Measurement Configuration
Register
Type: RW
Bit
Name
Default
Function
Comments
7
cm_d3
Definition of Δcm (difference to
0
reference which triggers
interrupt)
6
cm_d2
0
5
cm_d1
0
4
cm_d0
0
3
cm_aam
Include/exclude the
0
0: Exclude the IRQ measurement
1: Include the IRQ measurement
measurement which causes
IRQ (having difference > Δcm
to reference) in
auto-averaging
2
cm_aew1
1
cm_aew0
0
00: 4
01: 8
0
10: 16
11: 32
Define weight of last
measurement result for
auto-averaging
0
cm_ae
1: Use capacitance
0
measurement auto-averaging as
reference
Note: Default setting is set at power-up and after Set Default command.
ams Datasheet, Confidential: 2013-Oct [2-03]
AS3911 – 115