W925EP01 Datasheet, PDF (90/108 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925EP01/ W925EP01FG
DTMFR2.4=0 DTMF receiver works as a DTMF receiver
DTMFR2.4=1 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 6-12, 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 6-12, are determined by Low/ High
nibbles of PHxx. The hysteresis control formulas are list below.
Alert tone hysteresis
HAT=13mv + 3mv*X
X=PHAD<7:4>
DTMF hysteresis
HDTMF=6mv + 3mv*X
X=PHAD<3:0>
FSK hysteresis
HFSK=13mv + 3mv*X
X=PHFL<7:4>
FSK detector hysteresis
HFSKD=13mv + 3mv*X
X=PHFL<3:0>
Application Circuit
The analog interface circuit of W925EP01 shown in Figure 6-21 is a typical CPE system. The gain
control op-amp is set to unit gain to allow the electrical characteristics to be met in this application
circuit.
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