w925e625 ETC-unknow, w925e625 Datasheet - Page 54

• Manufacturer Part Number: w925e625
• Description: 8-bit Cid Microcontroller
• Manufacturer: ETC-unknow

6.16 Calling Identity Delivery (CID)
W925E/C625 provides type I and type II of CID system. Type I is on-hook calling with CID message
and type II is off-hook call on waiting. The CID function includes FSK decoder, dual tone alert signal
detector, ring detector and DTMF receiver. The FSK demodulation function can demodulate Bell 202
and ITU-T V.23 Frequency Shift keying (FSK) with 1200 baud rate. The Tone Alert Signal detect
function can detect dual tones of Bellcore Customer Premises Equipment(CPE) Tone Alerting
Signal(CAS) and BT Idle State and Loop State Tone Alert Signal. The line reversal for BT, ring burst
for CCA or ring signal for Bellcore can be detected by ring detector. It is compatible with Bellcore TR-
NWT-000030 & ST-TSV-002476, British Telecom(BT) SIN227, U.K. Cable Communications
Association(CCA) specification. The DTMF receiver can be programmed as DTMF decoder to decode
16 DTMF signals or tone detector to detect the signal which frequency is in DTMF band. The tone
detector can be an auxiliary detector to improve the performance of detecting tone alerting
signal(CAS), said as talk down-off, in type II system.
The FSK decoder, alert tone detector and DTMF receiver can be enable/disable individually by the bits
of FSKE, CASE and DTMFE in FSK DATA REGISTER(FSKDR). CIDE is the global control bit to
enable/disable FSK decoder, alert tone detector and DTMF receiver. However, the ring detector is
always active.
PS: The signals noted in italic and underline type are CID pins on the chip.
CIDE,RST
GCFB2
GCFB1
VADD
VASS
VREF
INN2
INN1
INP2
INP1
CAP
CIDGD
+
+
-
-
Bias Voltage
Generator
Input Pre-processor
Fm
Input Pre-processor
Clock Driver
PGAF
<3:0>
PGAF
<7:4>
To internal
circuit
CIDGA
Anti-alias
Anti-alias
Filter
Filter
To internal
circuit
PGD
<3:0>
PGD
<7:4>
Figure 6-17 The CID Block Diagram
Low Tone
High Tone
Bandpass
Bandpass
Filter
Filter
FSK Bandpass
DATE
Filter
High Tone
Low Tone
Bandpass
Bandpass
Filter
Filter
PHAD<7:4>
FSK Demodulation Circuit
PHAD<3:0>
Dual Tone Alert Signal Detection Circuit
- 54 -
PHFL<7:4>
PHFL<3:0>
High Tone
Low Tone
Detector
Detector
RNGDI
High Tone
Low Tone
Detector
Detector
Demodulator
FSK Carrier
Detector
FSK
DTMFE
Ring Detector
FSKE
RNGRC
Circuit
Guard
Time
Timer
Guard
Time
Data Output
Interface
FSK
ESt
Generator
Interrupt
Decode
data
and Latch
W925E/C625
DTMFPT/DTMFAT
CASPT/CASAT
RNG
FCD
FD7-FD0
FDR
DTMFD
DD3-DD0
ALGO
FDATA