CX81801-7x/8x SmartV.XX Modem Data Sheet
Table 3-12. CX20442 VC Pin Signal Definitions
Label
VDD
MAVDD
VSS
MAVSS
VSUB
POR
SET3V_BAR2
SLEEP
M_CLKIN
M_SCK
M_CNTRL_SIN
M_STROBE
M_TXSIN
M_RXOUT
M_MIC_IN
M_SPKR_OUT
Pin
17, 25
5
28
6
27
4
26
1
19
21
18
23
20
22
13
3
I/O
P
P
G
G
G
I
I
I
I
O
I
O
I
O
I
O
I/O Type
System Signals
PWR
PWR
GND
AGND
GND
Itpu
Itpu
Itpd
Itpd
Ot2
Itpd
Ot2
Itpd
Digital Power Supply.
Connect to +3.3V and digital circuits power
supply filter.
Analog Power Supply.
Connect to +3.3V and analog circuits
power supply filter.
Digital Ground.
Connect to GND.
Analog Ground.
Connect to AGND.
Analog Ground.
Connect to AGND.
Power-On Reset.
Active low reset input. Connect to Host
RESET# or reset circuit.
Set +3.3V Analog Reference.
Connect to GND.
IA Sleep.
Active high sleep input. Connect to CX81801 IASLEEP
pin.
Master Clock Input.
Connect to CX81801 M_CLK pin.
Serial Clock Output.
Connect to CX81801 V_SCLK pin.
Control Input.
Connect to CX81801 V_CTRL pin.
Serial Frame Sync.
Connect to CX81801 V_STROBE pin.
Serial Transmit Data.
Connect to CX81801 V_TXSIN pin.
Signal Name/Description
CX81801 Interconnect
Ot2
Serial Receive Data.
Connect to CX81801 V_RXOUT pin.
Microphone/Speaker Interface
I(DA)
O(DF)
Microphone Input.
Single-ended analog input from the
microphone circuit.
Modem Speaker Analog Output.
The M_SPKR_OUT analog
output reflects the received analog input signal. The
M_SPKR_OUT on/off and three levels of attenuation are controlled
by bits in DSP RAM. When the speaker is turned off, the
M_SPKR_OUT output is clamped to the voltage at the VC pin. The
M_SPKR_OUT output can drive an impedance as low as 300
Ω.
In
a typical application, the M_SPKR_OUT output is an input to an
external LM386 audio power amplifier.
Handset/Headset Interface
Telephone Handset Out (TELOUT).
Single-ended analog data
output to the telephone handset circuit. The output can drive a
300
Ω
load.
Telephone Handset Out (TELIN).
Single-ended analog data input
from the telephone handset circuit.
M_LINE_OUTP
9
O
O(DF)
M_LINE_IN
14
I
I(DA)
3-32
Conexant
102199B
CONEXANT [ CONEXANT SYSTEMS, INC ]
