msm7617 Oki Semiconductor, msm7617 Datasheet - Page 6

• Manufacturer Part Number: msm7617
• Description: 2-channel Echo Canceler
• Manufacturer: Oki Semiconductor

¡ Semiconductor
PIN DESCRIPTIONS (Continued)
Pin
10
11
13
14
15
16
9
Symbol
SYNC1
ADP1
NLP1
HCL1
RST1
ECM
SCK
Type
I
I
I
I
I
I
I
Common pin for channel 1 and channel 2. Clock input pin for PCM data
transmission.
Input the same clock as the transmit/receive clock of the PCM CODEC.
Frequencies below 128 kHz cannot be used in serial mode.
Not used. Fix input to "H".
NLP control pin for channel 1.
This pin controls center clipping, forcing SOUT1 output to the minimum
positive value when it is below –54 dBm0. It is effective for reducing
uncancelled echoes and low-level noise.
Sync signal input pin for channel 1 transmit/receive PCM data while in 2-
channel parallel I/O mode, 2-channel serial I/O mode, or 1-channel cross-
connected mode.
Input the transmit/receive sync signal (8 kHz) of the PCM CODEC.
Echo canceler disable control pin for channel 1.
This pin disables the echo canceler and enables data from SIN to SOUT to be output
in "through mode". The input and output levels of SIN and SOUT are changed by the
setting of the SG and SA pins; therefore, to output data from SIN to SOUT in "through
mode", set the SA and SG pins to "0 dB".
It simultaneously clears the adaptive FIR filter coefficients.
AFF coefficient control pin for channel 1.
This pin stops coefficient variation of the adaptive FIR filter (AFF), fixing the
coefficients. It allows once acquired AFF coefficients to be saved.
Reset signal input pin for channel 1.
Input signals are invalid for 100 ms after reset (after RST returns to "H" from
"L") for setting initial values.
Input the base clock during reset. Output pins will be placed in the following
states during reset.
"H": Center clipping on
"L": Center clipping off
"H": Disable mode
"L": Normal mode (echo canceler enabled)
"H": Fixed coefficient mode
"L": Normal mode (variable coefficients)
"L": Reset
"H": Normal operation
Hi-Z: ROUT1, SOUT1
No effect: SYNCO, SCKO, ROUT2, SOUT2, DF2, WDT2
Previous state: DF1, WDT1
Description
MSM7617
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