73K321L
CCITT V.23, V.21
Single-Chip Modem
April 2000
DESCRIPTION
The 73K321L is a highly integrated single-chip
modem IC which provides the functions needed to
construct a CCITT V.23 and V.21 compatible
modem, capable of 0-300 bit/s full-duplex or 0-1200
bit/s half-duplex operation over dial-up telephone
lines. The 73K321L provides 1200 bit/s operation in
V.23 mode and 300 bit/s in V.21 mode. The
73K321L also can both detect and generate the
2100 Hz answer tone needed for call initiation. The
73K321L integrates analog, digital, and switched-
capacitor array functions on a single substrate,
offering excellent performance and a high level of
functional integration in a single 28-pin DIP or PLCC
package. The 73K321L operates from a single +5V
supply with very low power consumption.
The
73K321L
includes
the
FSK
modulator/demodulator functions, call progress and
handshake tone monitor test modes, and a tone
generator capable of producing DTMF, answer,
calling tones. The 73K321L is designed to appear to
the systems designer as a microprocessor
peripheral, and will easily interface with popular one-
chip microprocessors (80C51 typical) for control of
modem functions through its 8-bit multiplexed
address/data bus or via an optional serial control
bus. An ALE control line simplifies address
demultiplexing.
Data
communications
occurs
through a separate serial port only.
(continued)
FEATURES
•
•
One-chip CCITT V.23 and V.21 standard
compatible modem data pump
Full-duplex operation at 0-300 bit/s (V.21) or
0-1200 bit/s ( .23) forward channel with or
V
without 0-75 bits/s back channel
Full Duplex 0-1200 bit/s (V.23) in 4-wire mode
Pin and software compatible with other TDK
Semiconductor Corporation K-Series 1-chip
modems
Interfaces directly with standard
processors (8048, 80C51 typical)
Serial port for data transfer
Call progress, carrier, precise answer tone
(2100 Hz), calling tone (1300 Hz) and FSK
mark detectors
DTMF generator
Test modes available: ALB, DL, RDL, Mark,
Space, Alternating bit patterns
Precise automatic gain control allows 45 dB
dynamic range
CMOS
technology
for
low
power
consumption using 60 mW @ 5V from a
single power supply
micro-
•
•
•
•
•
•
•
•
•
BLOCK DIAGRAM
DATA
BUS
BUFFER
DTMF &
TONE
GENERATORS
AD0-AD7
8-BIT
BUS
FOR
FSK
MODULATOR/
DEMODULATOR
RD
WR
ALE
CS
RESET
READ
WRITE
CONTROL
LOGIC
CONTROL
AND
STATUS
TRANSMIT
FILTER
RECEIVE
FILTER
TXA
RXA
INT
STATUS
AND
CONTROL
LOGIC
TXD
RXD
SERIAL
PORT
FOR
DATA
TESTS:
ALB,DLB
RDLB
PATTERNS
SMART
DIALING
&
DETECT
FUNCTIONS
CLOCK
GENERATOR
POWER
RXCLK
TXCLK
CLK
EXCLK
GND
XTL1
XTL2
VREF
VDD
ISET
TDK [ TDK ELECTRONICS ]
