參數(shù)資料
型號(hào): W925E625
英文描述: Telephone Controller
中文描述: 電話控制器
文件頁數(shù): 56/71頁
文件大?。?/td> 1055K
代理商: W925E625
W925E/C625
8-bit CID Microcontroller
Revision : A6
-56-
Release Date : 2002/7/2
ESt
Vin (Tip/ring)
TONE #n
t
DP
t
GP
t
REC
t
DA
t
GA
t
ABS
DTMFD
*
1
2
3
3
DTMFDR
Tone #n-1
Tone #n
* ESt is an internal signal in the circuit.
+ Clear by software.
Figure 6-22 The Waveform of DTMF Detection
Tone Detector
In off-hook state, said type II system, detecting tone alert signal(CAS) is easily interfered by
human’s voice or other noise in voice band. Sometimes the interference makes falsely
recognizing a noise as a CAS(talk-off), or lost detecting a real CAS(talk-down). The DTMF can be
programmed as a tone detector by setting bit 4 of DTMFR2. The frequency band of the tone
detector is DTMF frequency from 697Hz to 1633Hz. Once the tone detector gets signals in the
band, the bit of DTMFH or DTMFL in register DTMFDR will become high immediately. User can
poll these 2 bits to check if the tone exists on the tip/ring. The input gain of tone detector is the
same as DTMF receiver.
FSK Decoder
The FSK carrier detector provides an indication of the present of a signal within the FSK
frequency band. If the output amplitude of the FSK band-pass filter is sufficient to be detected
continuously for 8 mS, the FSK carrier detected bit FCD will go high and it will be released if the
FSK band-pass filter output amplitude is not able to be detected for greater than 8 mS. The 8 mS
is the hysteresis of the FSK carrier detector. Figure 6-23 shows the timing of FSK carrier
detection.
1: Guard time timer is reset and starts to up count from 00H.
2: Guard time timer is reset and starts to up count from 00H.
3: The content of the up counting timer reaches the register DTMFPT/DTMFAT.
DTMFDF
+
Tip/Ring
FCD
Analog FSK Signal
t
CP
t
CA
FSKE
t
FSKE
Analog FSK Signal
t
CP
t
CA
Note
Figure 6-23 FSK Detection Enable and FSK Carrier Present and Absent Timing
The FSK demodulation function can demodulate Bell 202 and ITU-T V.23 Frequency Shift keying
(FSK) with 1200 baud rate. When the decoder receives the FSK serial data, the serial data will be
demodulated into bit FDATA with 1200 baud rate in the mean time the synchronous clock signal
is output to the bit FCLK. As the decoder receives one byte, the internal serial-to-parallel circuit
相關(guān)PDF資料
PDF描述
W9320 A-Law/u-Law CODEC
W9320S A-Law/u-Law CODEC
W942508BH DRAM
W942516BH DRAM
W9451GBDA-6 SDRAM|DDR|64MX64|CMOS|DIMM|184PIN|PLASTIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
W925E625FG 功能描述:IC MCU 8-BIT W/CID 160-PQFP RoHS:是 類別:集成電路 (IC) >> 嵌入式 - 微控制器, 系列:W925 標(biāo)準(zhǔn)包裝:250 系列:80C 核心處理器:8051 芯體尺寸:8-位 速度:16MHz 連通性:EBI/EMI,I²C,UART/USART 外圍設(shè)備:POR,PWM,WDT 輸入/輸出數(shù):40 程序存儲(chǔ)器容量:- 程序存儲(chǔ)器類型:ROMless EEPROM 大小:- RAM 容量:256 x 8 電壓 - 電源 (Vcc/Vdd):4.5 V ~ 5.5 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 8x10b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:68-LCC(J 形引線) 包裝:帶卷 (TR)
W925EP01 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT CID MICROCONTROLLER
W925EP01FG 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT CID MICROCONTROLLER
W925G240 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-BIT CID MICROCONTROLLER
W925G625 制造商:WINBOND 制造商全稱:Winbond 功能描述:8-bit CID MICROCONTROLLER