PCF5083HSLASH5V2SLASHF3 datasheet(84/136 Pages) PHILIPS

84 / 136 page

1996 Oct 29

Philips Semiconductors

Objective speciﬁcation

GSM signal processing IC

PCF5083

SP_decoder_TCHFS

GSM full-rate speech decoder as deﬁned in

“GSM Rec. 06.01, 06.10, 06.11, 06.12, 06.31 and 06.32”. The following

tasks are performed:

Speech decoding algorithm.

Frame repetition and muting, in the event of a Bad Frame Indication (BFI)

and/or bad receive quality.

SID frame detection and Comfort Noise Insertion (CNI) in the event of

discontinuous transmission (DTX).

Integrated handsfree algorithm using a weighting balance and comfort

noise insertion.

The speech parameters in SCRATCH_BUFF are decoded. The audio

output data (see Table 32) is returned in SCRATCH_BUFF.

The three input parameters determine the operating mode of the speech

decoder. The dl_dtx_ﬂag enables DTX in down link when set. Note that the

dl_dtx_ﬂag should always be set to 1 except for test purposes.

The operation_mode consists of 3 ﬁelds: TMODE, HF and ATT. These

ﬁelds are shown in Table 62.

The TMODE ﬁeld is copied to the audio output data (bits TM0 to TM2

according to Table 36) in accordance with

“GSM recommendation 11.10,

section III.1.2.4.7”. TMODE can take the following values:

TMODE = 0; normal operation.

TMODE = 1; test of speech decoder. In this test mode an automatic reset of

the internal state variables is performed if a rising edge of the RESD bit

contained in the audio input data (deﬁned in Table 36) is detected.

TMODE = 2; test of speech encoder.

TMODE = 4; test of acoustic devices.

The HF fields enables (HF = 1) or disables (HF = 0) the handsfree mode of

the speech codec.

The ATT field has only a meaning in handsfree mode. It informs the

handsfree program about the attenuation between loudspeaker an

microphone in 3 dB steps. ATT = 0 means 0 dB, ATT = 7 means 21 dB. For

proper operation the ATT field has to be adjusted according to the volume

control of the loudspeaker. The arrangement of loudspeaker and

microphone has to be such that the attenuation at maximum volume level

does not exceed 0 dB.

The binary taf (time alignment ﬂag) marks with taf = 1 those trafﬁc frames

that are aligned with the SACCH multiframe structure deﬁned in

“GSM Rec. 05.08”.

dtx_ﬂag

taf

operation_mode

−

DESCRIPTION

PARAMETERS

RETURN

VALUES

PCF5083H/5V2/F3 数据表(PDF) 84 Page - NXP Semiconductors

PCF5083H/5V2/F3 数据表(HTML) 84 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载