
Semiconductor
MSM7603/7603B
5/20
PIN DESCRIPTIONS (Continued)
Pin
8
Symbol
RST
Type
I
Description
9
PWDWN
I
10
HD
I
12
CLKIN
I
16
SYNCO
O
This is the input pin for the reset signal.
"L": Reset mode
"H": Normal operation mode
Due to initialization, input signals are disabled for 100
m
s after reset
(after
RST
is returned from "L" to "H").
Input the basic clock during the reset.
Output pins during the reset are in the following sates :
High impedance: SOUT, ROUT
Not affected: SYNCO, SCKO
This is the power-down mode control pin for power down operation
"L": Power-down mode
"H": Normal operation mode
During power-down mode, all input pins are disabled and output
pins are in the following states :
High impedance : SOUT, ROUT
"L": SYNCO, SCKO
Reset after the power-down mode is released.
This pin controls the howling detect function that detects and
cancels a howling generated during hands-free talking for
acoustic system.
This function is used to cancel acoustic echoes.
"L": Howling detector ON
"H": Howling detector OFF
Used for MSM7603B only.
This is the input pin for
m
-law PCM/A-law PCM interface select
signal.
"L": A-law PCM interface
"H":
m
-law PCM interface
For MSM7603, apply V
DD
.
This is the input pin for external input for the basic clock.
Input the basic clock (17.5 to 20 MHz).
When the internal sync signal (SYNCO, SCKO) is used, input the
basic clock of 19.2 MHz.
This is the power supply pin for the PLL circuit used for the basic
clock.
Insert a 0.1
m
F capacitor with excellent high frequency
characteristics between V
DD
(PLL) and V
SS
(PLL).
This is the ground pin for the PLL circuit used for the basic clock.
This is the output pin for the 8 kHz sync signal for the PCM codec.
Connect to the SYNC pin and the PCM codec transmit/receive sync
pin.
Leave open if using an external SYNC.
11
(
m
/A)
I
13
V
DD
(PLL)
I
14
V
SS
(PLL)
I