000			02045naa a2200265 a 4500
003			AR-LpUFIB
005			20250311170418.0
008			230201s2003 xx o 000 0 eng d
024	8		_aDIF-M6549 _b6688 _zDIF005967
040			_aAR-LpUFIB _bspa _cAR-LpUFIB
100	1		_aJaquenod, Guillermo A.
245	1	0	_aEfficient tone detection solutions using programmable logic devices
300			_a1 archivo (211,7 KB)
500			_aFormato de archivo: PDF. -- Este documento es producción intelectual de la Facultad de Informática - UNLP (Colección BIPA/Biblioteca.) -- Disponible también en línea (Cons. 10/07/2014)
520			_aDigital solutions have been used for many years in central office and private automated branch exchange (PABX) designs. Although many functional blocks are available (ASICs or DSP solutions), only a few programmable logic solutions are known. Within a PABX and over E1 or T1 trunks, signals are digitized samples of audio, both for voice and signaling purposes. Dual Tone Multi Frequency (DTMF) is a standard where keystrokes from the telephone keypad are translated into dual tone signals over the audio link. Additionally, On/Off modulation of a 425 Hz signal, is used to identify the Call Progress Status (CPS): Dialing, Ringing, etc.. Special algorithms must be run to decode these signals, not only to detect the presence of tones, but also to ensure that voice signals can't be misdetected as DTMF. This paper describes a DTMF/CPS numeric coprocessor for detection task implemented using programmable logic devices (PLD). The same architecture, with different parameters, can be used to process other tone standards, such as ITU- R2 signaling.
534			_aWorkshop IBERCHIP (9º : 2003 mar. 26-28 : La Habana)
650		4	_aCIRCUITOS INTEGRADOS
650		4	_aESTÁNDARES
650		4	_aDISPOSITIVOS DE ENTRADA/SALIDA
650		4	_aPROGRAMACIÓN LÓGICA
700	1		_aVillagarcía Wanza, Horacio Alfredo
700	1		_aDe Giusti, Marisa Raquel
856	4	0	_uhttp://goo.gl/IkhZtZ
942			_cCP
999			_c55749 _d55749