msm7617-001 Oki Semiconductor, msm7617-001 Datasheet - Page 5

• Manufacturer Part Number: msm7617-001
• Description: 2-channel Echo Canceler
• Manufacturer: Oki Semiconductor

PIN DESCRIPTIONS
OKI Semiconductor
Pin
1
2
3
4
6
Symbol
SYNC2
ADP2
HCL2
RST2
NLP2
Type
I
I
I
I
I
Reset signal input pin for channel 2.
“L”: Reset
“H”: Normal operation
Input signals are invalid for 100 s after reset (after RST returns to “H” from “L”) for
setting initial values.
Input the basic clock during reset. Output pins will be placed in the following states
during reset.
Hi-Z: ROUT2, SOUT2
No effect: SYNCO, SCKO, ROUT1, SOUT1, DF1, WDT1
Previous state: DF2, WDT2
At power-up, keep this pin to "L" longer than 1 s after a master clock (CLKIN) gets
stably supplied, and execute initialization of LSI internal registers by releasing it to
"H".
Also such as in a case when this LSI is intended to be kept in reset state, for
instance, till the first call comes in, the above-mentioned initialization of LSI internal
registers must be done, and, later than 560ns since the initialization, assert this pin
back to "L" and wait the call.
AFF coefficient control pin for channel 2.
This pin stops coefficient variation of the adaptive FIR filter (AFF), fixing the
coefficients. It allows once acquired AFF coefficients to be saved.
“H”: Fixed coefficient mode
“L”: Normal mode (variable coefficients)
Echo canceler disable pin for channel 2.
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.
“H”: Disable mode
“L”: Normal mode (echo canceller enabled)
Sync signal input pin for channel 2 transmit/receive PCM data while in parallel I/O
mode.
Input the transmit/receive sync signal (8 kHz) of the PCM CODEC connected to
channel 2. Input “L” if not in parallel I/O mode.
NLP control pin for channel 2.
This pin controls center clipping, forcing SOUT2 output to the minimum positive
value when it is below –54 dBm0. It is effective for reducing uncanceled echoes
and low-level noise.
“H”: Center clipping on
“L”: Center clipping off
Description
MSM7617
5