W925E240 Datasheet, PDF (59/73 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925E/C240
DTMFR2
BIT3~BIT0
0000
0001
001X
01XX
1XXX
ACCEPTABLE ERROR PERCENTAGE TO SAMPLE 4 PERIOD OF COL FREQ.
0.5% (default)
1.5%
2.5%
Reserved
Reserved
The acceptable error percentage may have small variation by different test environments.
DTMFR2.4 = 0
DTMF receiver works as a DTMF receiver
DTMFR2.4 =
DTMF receiver works as a tone detector
DTMFR2.5 = 0
DTMF PT counter is up counter type, detected frequency changed does not
effect counter
DTMFR2.5 = 1
DTMF PT counter is up counter type, detected frequency changed resets
DTMF PT counter
DTMFR2.6 = 0
DTMF AT counter is up-down counter type, up counting when no DTMF
detected, down counting if DTMF detected again.
DTMFR2.6 = 1
DTMF AT counter is up counter type, up counting when no DTMF detected,
pause counting if DTMF detected again.
DTMFR2.7: reserved
There are 4 programmable gain arrays, shown in Figure 6-14, are determined by Low/High nibbles of
PGxx. The following table lists the input gain corresponding to the value of L/H nibble of PGxx.
X 20 LOG((40+15*X)/(230-(40+15*X))) DB
X
20 LOG((40+15*X)/(230-(40+15*X))) DB
0
-13.53
6
2.28
1
-10.05
7
4.64
2
-7.18
8
7.18
3
-4.64
9
10.05
4
-2.28
10
13.53
5
0.00
X is the value of L/H nibble of PGxx
There are 4 programmable hysteresis input buffer, shown in Figure 6-14, are determined by Low/ High
nibbles of PHxx. The hysteresis control formulas are list below.
Alert tone hysteresis
DTMF hysteresis
FSK hysteresis
FSK detector hysteresis
HAT = 13mv + 3mv*X
HDTMF = 6mv + 3mv*X
HFSK = 13mv + 3mv*X
HFSKD = 13mv + 3mv*X
X = PHAD<7:4>
X = PHAD<3:0>
X = PHFL<7:4>
X = PHFL<3:0>
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Publication Release Date: July 12, 2005
Revision A10