ETC 73K224BL-IGT

73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
April 2000
DESCRIPTION
FEATURES
The 73K224BL is a highly integrated single-chip
modem IC which provides the functions needed to
construct a V.22bis compatible modem, capable of
2400 bit/s full-duplex operation over dial-up lines.
The 73K224BL is an enhancement of the 73K224L
single-chip modem which adds the hybrid hook
switch control, and driver to the 73K224L. The
73K224BL integrates analog, digital, and switchedcapacitor array functions on a single chip, offering
excellent performance and a high level of functional
integration in a 32-Lead PLCC and 44-Lead TQFP
package.
•
Includes features of 73K224L single-chip
modem
•
On chip 2-wire/4-wire hybrid driver and off
hook relay buffer driver
•
One-chip multi-mode V.22bis/V.22/V.21 and
Bell 212A/103 compatible modem data pump
•
FSK (300 bit/s), DPSK (600, 1200 bit/s), or
QAM (2400 bit/s) encoding
•
Software compatible with other TDK
Semiconductor K-Series one-chip modems
•
Interfaces directly with standard
processors (80C51 typical)
•
•
Parallel or serial bus for control
•
All
asynchronous
and
synchronous
operating modes (internal, external, slave)
(continued)
The 73K224BL operates from a single +5 V supply
for low power consumption.
The 73K224BL is designed to appear to the systems
designer as a microprocessor peripheral, and will
easily interface with popular single-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 simplifies address demultiplexing. Data
communications normally occur through a separate
serial port.
Selectable internal buffer/debuffer
scrambler/descrambler functions
micro-
and
(continued)
BLOCK DIAGRAM
DTMF,
ANSWER,
GUARD &
CALLING
TONE
GENERATOR
OH
FSK
MODULATOR
BUFFER
SCRAMBLER
DI-BIT/
QUAD-BIT
ENCODER
FIR
PULSE
SHAPER
QAM/
DPSK
MODULATOR
EQUALIZER
FILTER
FILTER
ATTENUATOR
8-BIT
µP
BUS
INTERFACE
TXA1
2W/4W
HYBRID
DEBUFFER
DESCRAMBLER
DI-BIT/
QUAD-BIT
DECODER
DIGITAL
SIGNAL
PROCESSOR
RECEIVE
FUNCTIONS
FILTER
TXD
RXD
SERIAL
INTERFACE
TONE
DETECTION
RXA
A/D
EQUALIZER
FILTER
FILTER
FIXED
DEMODULATOR
TXA2
AGC
GAIN
BOOST
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DESCRIPTION (continued)
FEATURES (continued)
The 73K224BL is pin and software compatible with
the 73K222BL, allowing system upgrades with a
single component change.
The 73K224BL is designed to be a complete
V.22bis compatible modem on a chip. The
complete modem requires only the addition of the
phone line interface, a control microprocessor, and
RS-232 level converter for a typical system. Many
functions were included to simplify implementation
of typical modem designs. In addition to the basic
2400 bit/s QAM, 600/1200 bit/s DPSK and 300
bit/s FSK modulator/demodulator sections, the
device also includes synch/asynch converters,
scrambler/descrambler, call progress tone detect,
DTMF tone generator capabilities and handshake
pattern detectors. Test features such as analog
loop, digital loop, and remote digital loopback are
supported. Internal pattern generators are also
included for self-testing.
•
Adaptive equalization for optimum performance over all lines
•
Programmable transmit attenuation (16 dB,
1 dB steps), selectable receive boost (+18
dB)
•
Call progress, carrier, answer tone,
unscrambled mark, S1, and signal quality
monitors
•
DTMF, answer and guard tone generators
•
Test modes available: ALB, DL, RDL, mark,
space, alternating bit, S1 pattern generation
and detection
•
CMOS
technology
for
low
power
consumption (typically 100 mW @ 5 V) with
power-down mode (15 mW @ 5 V)
•
TTL and CMOS compatible inputs and
outputs
FUNCTIONAL DESCRIPTION
DPSK MODULATOR/DEMODULATOR
HYBRID AND RELAY DRIVER
The 73K224BL modulates a serial bit stream into
di-bit pairs that are represented by four possible
phase shifts as prescribed by the Bell 212A/V.22
standards. The base-band signal is then filtered to
reduce intersymbol interference on the bandlimited
2-wire PSTN line. Transmission occurs on either a
1200 Hz (originate mode) or 2400 Hz carrier
(answer mode). Demodulation is the reverse of
the modulation process, with the incoming analog
signal eventually decoded into di-bits and
converted back to a serial bit stream. The
demodulator also recovers the clock which was
encoded into the analog signal during modulation.
Demodulation occurs using either a 1200 Hz
carrier (answer mode or ALB originate mode) or a
2400 Hz carrier (originate mode or ALB answer
mode). Adaptive equalization is also used in
DPSK modes for optimum operation with varying
line conditions.
To make designs more cost effective and space
efficient, the 73K224BL includes the 2-wire to 4wire hybrid with sufficient drive to interface directly
to the telecom coupling transformers. In addition,
an off hook relay driver with 30mA drive capability
is also included to allow use of commonly
available mechanical telecom relays.
QAM MODULATOR/DEMODULATOR
The 73K224BL encodes incoming data into quadbits represented by 16 possible signal points with
specific phase and amplitude levels. The baseband signal is then filtered to reduce intersymbol
interference on the band limited telephone
network. The modulator transmits this encoded
data using either a 1200 Hz (originate mode) or
2400 Hz (answer mode) carrier. The demodulator,
although more complex, essentially reverses this
procedure while also recovering the data clock
from the incoming signal. Adaptive equalization
corrects
for varying line
conditions
by
automatically changing filter parameters to
compensate for line characteristics.
FSK MODULATOR/DEMODULATOR
The FSK modulator produces a frequency
modulated analog output signal using two discrete
frequencies to represent the binary data. The Bell
103 standard frequencies of 1270 and 1070 Hz
2
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
The synch/asynch converter also has an extended
overspeed mode which allows selection of an output
overspeed range of either +1% or +2.3%. In the
extended overspeed mode, stop bits are output at 7/8
rising edge of TXCLK the normal width.
FUNCTIONAL DESCRIPTION (continued)
(originate mark and space) and 2225 and 2025 Hz
(answer mark and space) are used when this
mode is selected. V.21 mode uses 980 and 1180
Hz (originate, mark and space) or 1650 and 1850
Hz (answer, mark and space). Demodulation
involves detecting the received frequencies and
decoding them into the appropriate binary value.
The rate converter and scrambler/descrambler are
automatically bypassed in the FSK modes.
Both the synch/asynch rate converter and the data
descrambler are automatically bypassed in the
FSK modes.
SYNCHRONOUS MODE
Synchronous operation is possible only in the
QAM or DPSK modes. Operation is similar to that
of the asynchronous mode except that data must
be synchronized to a provided clock and no
variation in data transfer rate is allowable. Serial
input data appearing at TXD must be valid on the
rising edge of TXCLK.
PASSBAND FILTERS AND EQUALIZERS
High and low band filters are included to shape the
amplitude and phase response of the transmit and
receive signals and provide compromise delay
equalization and rejection of out-of-band signals.
Amplitude and phase equalization are necessary
to compensate for distortion of the transmission
line and to reduce intersymbol interference in the
band limited receive signal. The transmit signal
filtering corresponds to a 75% square root of
raised Cosine frequency response characteristic.
TXCLK is an internally derived 1200 or 2400 Hz
signal in internal mode and is connected internally
to the RXCLK pin in slave mode. Receive data at
the RXD pin is clocked out on the falling edge of
RXCLK. The asynch/synch converter is bypassed
when synchronous mode is selected and data is
transmitted at the same rate as it is input.
ASYNCHRONOUS MODE
The asynchronous mode is used for communication
with
asynchronous
terminals
which
may
communicate at 600,1200, or 2400 bit/s +1%, 2.5% even though the modem’s output is limited to
the nominal bit rate ±.01% in DPSK and QAM
modes. When transmitting in this mode the serial
data on the TXD input is passed through a rate
converter which inserts or deletes stop bits in the
serial bit stream in order to output a signal that is
the nominal bit rate ±.01%. This signal is then
routed to a data scrambler and into the analog
modulator where quad-bit/di-bit encoding results in
the output signal. Both the rate converter and
scrambler can be bypassed for handshaking, and
synchronous operation as selected. Received data
is processed in a similar fashion except that the rate
converter now acts to reinsert any deleted stop bits
and output data to the terminal at no greater than
the bit rate plus 1%. An incoming break signal (low
through two characters) will be passed through
without incorrectly inserting a stop bit.
PARALLEL BUS CONTROL INTERFACE MODE
Eight 8-bit registers are provided for control, option
select, and status monitoring. These registers are
addressed with the AD0, AD1, and AD2
multiplexed address lines (latched by ALE) and
appear to a control microprocessor as seven
consecutive memory locations. Six control
registers are read/write memory. The detect and
ID registers are read only and cannot be modified
except by modem response to monitored
parameters.
3
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
SERIAL CONTROL INTERFACE MODE
The serial Command mode allows access to the
73K224BL control and status registers via a serial
control port. In this mode the AD0, AD1, and AD2
lines provide register addresses for data passed
through the AD7 (DATA) pin under control of the
RD and WR lines. A read operation is initiated
when the RD line is taken low. The next eight
cycles of EXCLK will then transfer out eight bits of
the selected address location LSB first. A write
takes place by shifting in eight bits of data LSB
first for eight consecutive cycles of EXCLK. WR is
then pulsed low and data transfer into the selected
register occurs on the rising edge of WR.
DTMF GENERATOR
The DTMF generator controls the sending of the
sixteen standard DTMF tone pairs. The tone pair
sent is determined by selecting transmit DTMF (bit
D4) and the 4 DTMF bits (D0-D3) of the Tone
Register. Transmission of DTMF tones from TXA
is gated by the transmit enable bit of CR0 (bit D1)
as with all other analog signals.
4
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
PIN DESCRIPTION
POWER
NAME
PIN
TYPE
DESCRIPTION
GND
1
I
System ground
VDD
16
I
Power supply input, 5 V ±10% (73K224BL). Bypass with 0.1
and 22 µF capacitors to GND.
VREF
31
O
An internally generated reference voltage. Bypass with
0.1 µF capacitor to ground.
ISET
28
I
Chip current reference. Sets bias current for op-amps. The
chip current is set by connecting this pin to VDD through a
2 MΩ resistor. ISET should be bypassed to GND with a
0.1 µF capacitor.
PARALLEL MICROPROCESSOR CONTROL INTERFACE MODE
ALE
13
I
ADDRESS LATCH ENABLE: The falling edge of ALE latches
the address on AD0-AD2 and the chip select on CS.
5-12
I/O
ADDRESS/DATA BUS: These bi-directional tri-state
multiplexed lines carry information to and from the internal
registers.
CS
23
I
CHIP SELECT: A low on this pin during the falling edge of
ALE allows a read cycle or a write cycle to occur. AD0-AD7
will not be driven and no registers will be written if CS
(latched) is not active. The state of CS is latched on the
falling edge of ALE.
CLK
2
O
OUTPUT CLOCK: This pin is selectable under processor
control to be either the crystal frequency (for use as a
processor clock) or 16 times the data rate for use as a baud
rate clock in DPSK modes only. The pin defaults to the
crystal frequency on reset.
INT
20
O
INTERRUPT: This open drain output signal is used to inform
the processor that a detect flag has occurred. The processor
must then read the Detect Register to determine which detect
triggered the interrupt. INT will stay low until the processor
reads the detect register or does a full reset.
RD
15
I
READ: A low requests a read of the 73K224BL internal
registers. Data can not be output unless both RD and the
latched CS are active or low.
RESET
30
I
RESET: An active high signal on this pin will put the chip into
an inactive state. All Control Register bits (CR0, CR1, tone)
will be reset. The output of the CLK pin will be set to the
crystal frequency. An internal pull-down resistor permits
power-on-reset using a capacitor to VDD.
AD0-AD7
5
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
PARALLEL MICROPROCESSOR INTERFACE (continued)
NAME
PIN
TYPE
WR
14
I
DESCRIPTION
WRITE: A low on this informs the 73K224BL that data is
available on AD0-AD7 for writing into an internal register.
Data is latched on the rising edge of WR. No data is written
unless both WR and the latched CS are low.
SERIAL MICROPROCESSOR CONTROL INTERFACE MODE
NAME
PIN
TYPE
DESCRIPTION
AD0-AD2
5-7
I
REGISTER ADDRESS SELECTION: These lines carry
register addresses and should be valid during any read or
write operation.
DATA (AD7)
12
I/O
SERIAL CONTROL DATA: Data for a read/write operation is
clocked in or out on the falling edge of the EXCLK pin. The
direction of data flow is controlled by the RD pin. RD low
outputs data. RD high inputs data.
RD
15
I
READ: A low on this input informs the 73K224BL that data or
status information is being read by the processor. The falling
edge of the RD signal will initiate a read from the addressed
register. The RD signal must continue for eight falling edges
of EXCLK in order to read all eight bits of the referenced
register. Read data is provided LSB first. Data will not be
output unless the RD signal is active.
WR
14
I
WRITE: A low on this input informs the 73K224BL that data
or status information has been shifted in through the DATA
pin and is available for writing to an internal register. The
normal procedure for a write is to shift in data LSB first on the
DATA pin for eight consecutive falling edges of EXCLK and
then to pulse WR low. Data is written on the rising edge of
WR.
NOTE: The serial control mode is provided by tying ALE high and CS low. In this configuration AD7 becomes
DATA and AD0, AD1 and AD2 become the register address.
6
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DTE USER
NAME
PIN
TYPE
DESCRIPTION
EXCLK
22
I
EXTERNAL CLOCK: This signal is used in synchronous
transmission when the external timing option has been
selected. In the external timing mode the rising edge of
EXCLK is used to strobe synchronous DPSK transmit data
applied to on the TXD pin. Also used for serial control
interface.
RXCLK
26
O
RECEIVE CLOCK: The falling edge of this clock output is
coincident with the transitions in the serial received data
output. The rising edge of RXCLK can be used to latch the
valid output data. RXCLK will be valid as long as a carrier is
present.
RXD
25
O
RECEIVED DATA OUTPUT: Serial receive data is available
on this pin. The data is always valid on the rising edge of
RXCLK when in synchronous mode. RXD will output
constant marks if no carrier is detected.
TXCLK
21
O
TRANSMIT CLOCK: This signal is used in synchronous
transmission to latch serial input data on the TXD pin. Data
must be provided so that valid data is available on the rising
edge of the TXCLK. The transmit clock is derived from
different sources depending upon the synchronization mode
selection. In internal mode the clock is generated internally.
In external mode TXCLK is phase locked to the EXCLK pin.
In slave mode TXCLK is phase locked to the RXCLK pin.
TXCLK is always active.
TXD
24
I
TRANSMIT DATA INPUT: Serial data for transmission is
applied on this pin. In synchronous modes, the data must be
valid on the rising edge of the TXCLK clock. In asynchronous
modes (1200/600 bit/s or 300 baud) no clocking is
necessary. DPSK data must be 1200/600 bit/s +1%, -2.5% or
+2.3%, -2.5 % in extended over speed mode.
.
7
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
PIN DESCRIPTION (continued)
ANALOG INTERFACE AND OSCILLATOR
NAME
PIN
TYPE
RXA
32
I
Received modulated analog signal input from the telephone
line interface.
TXA1 / TXA2
18 / 17
O
Transmit Analog (differential outputs): These pins provide the
analog output signals to be transmitted to the telephone line.
The drivers will differentially drive the impedance of the line
transformer and the line matching resistor. An external hybrid
can also be built using TXA1 as a single ended transmit
signal.
XTL1 / XTL2
3/4
I
These pins are for the internal crystal oscillator requiring a
11.0592 MHz parallel mode crystal. Load capacitors should
be connected from XTL1 and XTL2 to ground. XTL2 can also
be driven from an external clock.
27
O
OFF-HOOK RELAY DRIVER: This signal is an open drain
output capable of sinking 30mA and is used for controlling a
relay. The output is the complement of the OH register bit in
the ID Register.
OH
DESCRIPTION
.
8
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
REGISTER ADDRESS TABLE
ADDRESS
REGISTER
CONTROL
REGISTER
0
CR0
DATA BIT NUMBER
AD2 - AD0
D7
D6
D5
D4
D3
D2
D1
D0
000
MODULATION
OPTION
MODULATION
TYPE
1
MODULATION
TYPE
0
TRANSMIT
MODE
2
TRANSMIT
MODE
1
TRANSMIT
MODE
0
TRANSMIT
ENABLE
ORIGINATE/
ANSWER
QAM: 0 = 2400 BIT/S
DPSK: 0=1200 BIT/S
1 = 600 BIT/S
FSK: 0 = 103 MODE
1 = V.21
CONTROL
REGISTER
1
CR1
001
TRANSMIT
PATTERN
1
10=QA,
00=DPSK
01=FSK
TRANSMIT
PATTERN
0
00 = TX DATA
01 = TX ALTERNATE
(DOTTING)
10 = TX MARK
11 = TX SPACE
DETECT
REGISTER
READ ONLY
DR
010
RECEIVE
LEVEL
INDICATOR
ENABLE
DETECT
INTERRUPT
0 = DISABLE
1 = ENABLE
S1
PATTERN
DETECT
RECEIVE
DATA
BYPASS
SCRAMBLER
TR
011
RXD
OUTPUT
CONTROL
RXD PIN
0 = NORMAL
1 = OPEN
CONTROL
REGISTER
2
CONTROL
REGISTER
3
CR2
CR3
100
101
0
TXDALT
ALTERNATE
TRANSMIT
DATA
SOURCE
SPECIAL
REGISTER
SR
101
0
TRANSMIT
GUARD/
TONE
TRANSMIT
ANSWER
TONE
0 = OFF
1 = ON
0 = OFF
1 = ON
SPECIAL
REGISTER
ACCESS
CALL
INTIALIZE
CLK
CONTROL
TEST
MODE
1
RESET
0 = NORMAL
0 = XTAL
0 = NORMAL
1 = BYPASS
1 = 16 X DATA
1 = RESET
SCRAMBLER RATE OUTPUT
AT CLK PIN IN
QAM/DPSK MODE
ONLY
UNSCR.
MARKS
DETECT
0=SIGNAL
0=NOT PRESENT OUTPUTS
BELOW
1=PATTERN
RECEIVED
THRESHOLD
FOUND
DATA STREAM
1=ABOVE
THRESHOLD
TONE
CONTROL
REGISTER
0 = ANSWER
0 = DISABLE
TXA OUTPUT 1 = ORIGINATE
1 = ENABLE
TXA OUTPUT
0000 = PWR DOWN
0001 = INT SYNCH
0010 = EXT SYNCH
0011 = SLAVE SYNCH
0100 = ASYNCH 8 BITS/CHAR
0101 = ASYNCH 9 BITS/CHAR
0110 = ASYNCH 10 BITS/CHAR
0111 = ASYNCH 11 BITS/CHAR
1X00 = FSK
CARRIER
DETECT
ANSWER
TONE
DETECT
00 = NORMAL
01 = ANALOG LOOPBACK
10 = REMOTE DIGITAL
LOOPBACK
11 = LOCAL DIGITAL
LOOPBACK
CP
TONE
DETECT
0 = CONDITION NOT DETECTED
1 = CONDITION DETECTED
TRANSMIT
DTMF
0 = DATA
CARRIER
1=TX DTMF
TRANSMIT
S1
DTMF2/
4W/FDX
DTMF3
DTMF1/
EXTENDED
OVERSPEED
RESET
DSP
TRAIN
INHIBIT
0=RX=TX
1=RX=16WAY
TX=4WAY
IN DPSK
0=DSP
INACTIVE
1=DSP
ACTIVE
0=ADAPT EQ
ACTIVE
1=ADAPT EQ
FROZEN
RECEIVE
GAIN
BOOST
TRANSMIT
ATTEN.
3
TRANSMIT
ATTEN.
2
TRANSMIT
ATTEN.
1
0=NORMAL
1=TRISTATE
TX BAUD
CLOCK
OUTPUTS
TXBAUD
CLOCK
OH
0=OH RELAY
0=NO BOOST
DRIVER OPEN 1=18 dB BOOST
1=OH OPEN
DRAIN
DRIVER PULLING
LOW
RX UNSCR.
DATA
OUTPUTS
UNSCR.
DATA
EQUALIZER
ENABLE
0=ADAPT EQ
IN RESET STATE
1=ADAPT EQ
ACTIVE
TRANSMIT
ATTEN.
0
0000-1111,SETS
TRANSMIT ATTENUATOR
16 dB RANGE
DEFAULT=0100 -10 dBm0
TXD
SOURCE
0
DTMF0/
GUARD/
ANSWER
0 = 1800 Hz G.T.
2225 Hz ANNS TONE
GENERATED
1 = 550 Hz ANS TONE
2100 Hz ANS TONE
GENERATED &
DETECTED (V.21, V.22)
0=NORMAL
0=ACCESS CR3 0=DSP IN
DEMOD MODE
DOTTING
1=ACCESS
1=DSP IN CALL
1=S1
SPECIAL
PROGRESS
REGISTER
MODE
TRISTATE
TX/RXCLK
SIGNAL
QUALITY
INDICATOR
0=GOOD
1=BAD
4 BIT CODE FOR 1 OF 16
DUAL TONE COMBINATIONS
16 WAY
TEST
MODE
0
0=TXD PIN
1=TXALT BIT
SQ
SELECT 1
SQ
SELECT 0
0
00 10 -5 BER
01 10 -6 BER
10 10 -4 BER
11 10 -3 BER
ID
REGISTER
READ ONLY
10
110
00XX=73K212AL, 322L, 321L
01XX=73K221AL, 302L
10XX=73K222AL, 222BL
1100=73K224L, 224BL
1110=73K324L, 324BL
1
1
0
0
X
0 = Only write zeros to these locations
X = Undefined, mask in software
9
X
X
X
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CONTROL REGISTER 0
CR0
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
000
MODUL.
OPTION
MODUL.
TYPE 1
MODUL.
TYPE 0
TRANSMIT
MODE 2
TRANSMIT
MODE 1
TRANSMIT
MODE 0
TRANSMIT
ENABLE
ANSWER/
ORIGINATE
BIT
D0
NAME
Answer/
Originate
CONDITION
0
DESCRIPTION
Selects answer mode (transmit in high band, receive
in low band).
Selects originate mode (transmit in low band, receive in
high band).
Disables transmit output at TXA1 & TXA2
Enables transmit output at TXA1 & TXA2
Note: Transmit enable must be set to 1 to allow
activation of answer tone or DTMF.
1
D1
Transmit
Enable
0
1
D5,D4
D3,D2
Transmit
Mode
D5 D4 D3 D2
0 0 0 0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
D6,D5
Modulation
Type
X 0
D6 D5
1
0
0 0
0 1
0
Selects Power down mode. All functions disabled except
digital interface..
Internal synchronous mode in this mode TXCLK is an
internally derived 600,1200 or 2400 Hz signal. Serial
input data appearing at TXD must be valid on the rising
edge of TXCLK. Receive data is clocked out of RXD on
the falling edge of RXCLK.
External synchronous mode. Operation is identical to
internal synchronous, but TXCLK is connected internally
to EXCLK pin, and a 600, 1200 or 2400 Hz clock must be
supplied externally.
Slave synchronous mode Same operation as other
synchronous modes TXCLK is connected internally to
the RXCLK pin in this mode.
Selects a synchronous mode 8 bits/character (1 start bit,
6 data bits, 1 stop bit).
Selects asynchronous mode - 9 bits/character (1 start bit,
7 data bits, 1 stop bit).
Selects asynchronous mode - 10 bits/character (1 start
bit, 8 data bits, 1 stop bit).
Selects asynchronous mode - 11 bits/character (1 start
bit, 8 data bits, 1 stop bit) or 2 stop bits)..
Selects FSK operation.
QAM
DPSK
FSK
10
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CONTROL REGISTER 0 (continued)
CR0
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
000
MODUL.
OPTION
MODUL.
TYPE 1
MODUL.
TYPE 0
TRANSMIT
MODE 2
TRANSMIT
MODE 1
TRANSMIT
MODE 0
TRANSMIT
ENABLE
ANSWER/
ORIGINATE
BIT
NAME
CONDITION
DESCRIPTION
D7
Modulation
Option
0
QAM selects 2400 bit/s. DPSK selects 1200 bit/s.
FSK selects 103 mode.
1
DPSK selects 600 bit/s.
FSK selects V.21 mode.
CONTROL REGISTER 1
CR1
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
001
TRANSMIT
PATTERN
1
TRANSMIT
PATTERN
0
ENABLE
DETECT
INTERRUPT
BYPASS
SCRAMBLER
CLOCK
CONTROL
RESET
TEST
MODE 1
TEST
MODE 0
BIT
D0, D1
D2
D3
NAME
Test Mode
Reset
Clock Control
CONDITION
DESCRIPTION
D1
D0
0
0
Selects normal operating mode
0
1
Analog loopback mode. Loops the transmitted analog
signal back to the receiver, and causes the receiver to
use the same carrier frequency as the transmitter. To
squelch the TXA pin, transmit enable bit as well as Tone
Register bit D2 must be low.
1
0
Selects remote digital loopback. Received data is looped
back to transmit data internally, and RXD is forced to a
mark. Data on TXD is ignored.
1
1
Selects local digital loopback. Internally loops TXD back
to RXD and continues to transmit data carrier at TXA pin
0
Selects Normal Operations
1
Resets modem to power-down state.
All Control
Register bits (CR0, CR1, CR2, CR3 and tone) are reset
to zero except CR3 bit D2. The output of the clock pin
will be set to the crystal frequency.
0
Selects 11.0592 MHz crystal echo output at CLK pin
1
Selects 16 times the data rate output at CLK pin in
DPSK/QAM modes only.
11
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CONTROL REGISTER 1 (continued)
CR1
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
001
TRANSMIT
PATTERN
1
TRANSMIT
PATTERN
0
ENABLE
DETECT
INTERRUPT
BYPASS
SCRAMBLER
CLOCK
CONTROL
RESET
TEST
MODE 1
TEST
MODE 0
BIT
NAME
CONDITION
D4
Bypass
Scrambler
0
Selects normal operation.
passed through scrambler.
1
Selects Scrambler bypass. Bypass DPSK and QAM
data is route around scrambler in the transmit path.
0
Disables interrupt at INT pin. All interrupts are normally
disabled in power-down mode.
1
Enables INT output. An interrupt will be generated with a
change in status of DR bits D1- D4 and D6. The answer
tone and call progress detect interrupts are masked
when the TX enable bit is set. Carrier detect is masked
when TXDTMF is activated.
All interrupts will be
disabled if the device is in power-down mode.
D5
Enable Detect
Interrupt
DESCRIPTION
DPSK and QAM data is
D7 D6
D6, D7
Transmit
Pattern
0
0
Selects normal data transmission as controlled by the
state of the TXDpin.
0
1
Selects an alternating mar/space transmit pattern for
modem testing and handshaking. Also used for S1
pattern generation (see CR2 bit D4).
1
0
Selects a constant mark transmit pattern.
1
1
Selects a constant space transmit pattern.
DETECT REGISTER
DR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
010
RECEIVE
LEVEL
INDICATOR
S1
PATTERN
DETECT
RECEIVE
DATA
UNSCR.
MARK
DETECT
CARR.
DETECT
ANSWER
TONES
DETECT
CALL
PROG.
DETECT
SIGNAL
QUALITY
INDICATOR
BIT
NAME
CONDITION
D0
Signal Quality
0
Indicates normal received signal.
Indicator
1
Indicates low received signal quality (above average
error rate). Interacts with Special Register bits D2, D1.
Call Progress
0
No call progress tone detected.
Detect
1
Indicates presence of call progress tones. The call
progress detection circuitry is activated by energy in the
normal 350 to 620 Hz call progress bandwidth.
D1
DESCRIPTION
12
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DETECT REGISTER (continued)
DR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
010
RECEIVE
LEVEL
INDICATOR
S1
PATTERN
DETECT
RECEIVE
DATA
UNSCR.
MARK
DETECT
CARR.
DETECT
ANSWER
TONES
DETECT
CALL
PROG.
DETECT
SIGNAL
QUALITY
INDICATOR
BIT
NAME
CONDITION
D2
Answer Tone
0
No answer tone detected.
Received
1
In call init mode, indicates detection of 2225 Hz answer
tone in Bell mode (TR bit D0 = 0) or 2100 Hz if in CCITT
mode (TR bit D0 = 1). The device must be in originate
mode for detection of answer tone. Both answer tones
are detected in demodulation mode.
Carrier Detect
0
No carrier detected in the receive channel.
1
Indicated carrier has been detected in the received
channel.
Unscrambled
0
No unscrambled mark.
Mark Detect
1
Indicates detection of unscrambled marks in the received
data. Should be time qualified by software.
D3
D4
DESCRIPTION
D5
Receive Data
D6
S1 Pattern
0
No S1 pattern being received.
Detect
1
S1 pattern detected. Should be time qualified by
software. S1 pattern is defined as a double di-bit
(001100..) unscrambled 1200 bit/s DPSK signal. Pattern
must be aligned with baud clock to be detected.
Receive Level
Indicator
0
Received signal level below threshold, (typical ≈ -25 dBm0);
can use receive gain boost (+18 dB).
1
Received signal above threshold.
D7
Continuously outputs the received data stream. This data
is the same as that output on the RXD pin, but it is not
disabled when RXD is tri-stated.
13
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
TONE REGISTER
TR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
011
RXD
OUTPUT
CONTROL
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2/
4-WIRE
FDX
DTMF 1/
EXTENDED
OVERSPEED
DTMF 0/
ANSWER
GUARD
BIT
D0
D1
D2
NAME
CONDITION
DESCRIPTION
D6 D5 D4 D0
D0 interacts with bits D6, D5, and D4 as shown
DTMF 0/
X
X
1
X
Transmit DTMF tones must be in DPSK or Bell 103
mode.
Answer/
Guard Tone
X
1
0
0
Select Bell mode answer tone. Interacts with DR bit D2
and TR bit D5.
X
1
0
1
Select CCITT mode answer tone. Interacts with DR bit
D2 and TR bit D5.
1
0
0
0
Select 1800 Hz guard tone.
1
0
0
1
Select 550 Hz guard tone.
D4
D1
DTMF 1/
0
0
Asynchronous QAM or DPSK +1% -2.5%. (normal)
Extended
Overspeed
0
1
Asynchronous QAM or DPSK +2.3% -2.5%. (extended
overspeed)
D4
D2
DTMF 2/
0
0
Selects 2-wire duplex or half duplex
4 Wire FDX
0
1
D2 selects 4-wire full duplex in the modulation mode
selected. The receive path corresponds to the receive
mode selected by the ANS/ORIG bit CR0 D0 in terms of
high or low band selection. The transmitter is in the same
band as the receiver, but does not have magnitude
filtering or equalization on its signal as in the receive
path.
D1 interacts with D4 as shown.
14
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
TONE REGISTER
TR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
011
RXD
OUTPUT
CONTROL
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2/
4-WIRE
FDX
DTMF 1/
EXTENDED
OVERSPEED
DTMF 0/
ANSWER
GUARD
BIT
D3, D2,
D1, D0
NAME
CONDITION
DTMF 3,
2, 1, 0
DESCRIPTION
D0 interacts with bits D6, D5, and D4 as shown
Programs 1 of 16 DTMF tone pairs that will be
transmitted when TX DTMF and TX enable bit (CR0, bit
D1) is set. Tone encoding is shown below:
DTMF CODE
D3 D2 D1 D0
0
0
0
1
KEYBOARD
EQUIVALENT
1
0
0
1
0
2
697
1336
0
0
1
1
3
697
1477
0
4
770
1209
1
5
770
1336
0
6
770
1477
1
7
852
1209
852
1336
0
0
0
0
D4
1
0
1
0
1
1
1
1
TONES
LOW
HIGH
697
1209
1
0
0
0
8
1
0
0
1
9
852
1477
1
0
1
0
0
941
1336
1
0
1
1
*
941
1209
1
1
0
0
#
941
1477
1
1
0
1
A
697
1633
1
1
1
0
B
770
1633
1
1
1
1
C
852
1633
0
0
0
0
D
941
1633
TX DTMF
0
Disable DTMF.
(Transmit
DTMF)
1
Activate DTMF. The selected DTMF tones are
transmitted continuously when this bit is high. TX DTMF
overrides all other transmit functions.
NOTE: DTMF0-DTMF2 should be set to an appropriate state after DTMF dialing to avoid unintended
operation.
15
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
TONE REGISTER (continued)
TR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
011
RXD
OUTPUT
CONTROL
TRANSMIT
GUARD
TONE
TRANSMIT
ANSWER
TONE
TRANSMIT
DTMF
DTMF 3
DTMF 2/
4-WIRE
FDX
DTMF 1/
EXTENDED
OVERSPEED
DTMF 0/
ANSWER
GUARD
BIT
D5
D6
D7
NAME
CONDITION
DESCRIPTION
D5
D4
D0
Transmit
0
0
X
Disables answer tone generator.
Answer Tone
1
0
0
In answer mode, a Bell 2225 Hz tone is transmitted
continuously when the transmit enable bit is set.
1
0
1
Likewise, a CCITT 2100 Hz answer tone is transmitted.
D5 interacts with bits D4 and D0 as shown. Also interacts
with DR bit D2 in originate mode (see Detect Register
description).
Transmit
0
Disables guard tone generator.
Guard Tone
1
Enables guard tone generator (see D0 for selection of
guard tones). Bit D4 must be zero.
RXD Output
0
Enables RXD pin. Receive data will be output on RXD.
Control
1
Disables RXD pin. The RXD pin reverts to a high
impedance with internal weak pull-up resistor.
16
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CONTROL REGISTER 2
CR2
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
100
0
SPEC REG
ACCESS
CALL INIT
TRANSMIT S1
16 WAY
RESET
DSP
TRAIN
INHIBIT
EQUALIZER
ENABLE
BIT
NAME
CONDITION
D0
Equalizer
0
The adaptive equalizer is in its initialized state.
Enable
1
The adaptive equalizer is enabled. This bit is used in
handshakes to control when the equalizer should
calculate its coefficients.
Train Inhibit
0
The adaptive equalizer is active.
1
The adaptive equalizer coefficients are frozen.
0
The DSP is inactive and all variables are initialized.
1
The DSP is running based on the mode set by other
control bits.
0
The receiver and transmitter are using the same decision
plane (based on the modulator control mode).
1
The receiver, independent of the transmitter, is forced
into a 16 point decision plane. Used for QAM
handshaking.
0
The transmitter when placed in alternating mark/space
mode transmits 0101...... scrambled or not dependent on
the bypass scrambler bit.
1
When this bit is 1 and only when the transmitter is placed
in alternating mark/space mode by CR1 bits D7, D6, and
in DPSK or QAM, an unscrambled repetitive double di-bit
pattern of 00 and 11 at 1200 bit/s (S1) is sent.
0
The DSP is set-up to do demodulation and pattern
detection based on the various mode bits. Both answer
tones are detected in demodulation mode concurrently;
TR-D0 is ignored.
1
The DSP decodes unscrambled mark, answer tone and
call progress tones.
0
Normal CR3 access.
1
Setting this bit and addressing CR3 allows access to the
special register (see the special register for details).
0
Only write zero to this bit.
D1
D2
D3
D4
D5
D6
D7
RESET DSP
16 Way
Transmit S1
Call Init
Special
Register
Access
Not used at this time
DESCRIPTION
17
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CONTROL REGISTER 3
CR3
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
101
TXDALT
TRI-STATE
TX/RXCLK
OH
RECEIVE
BOOST
ENABLE
TRANSMIT
ATTEN. 3
TRANSMIT
ATEN 2
TRANSMIT
ATTEN. 1
TRANSMIT
ATTEN. 0
BIT
NAME
CONDITION
DESCRIPTION
D3 D2 D1 D0
D3, D2,
D1,D0
D4
D5
D6
D7
Transmit
Attenuator
0
1
0
1
0
1
0
1
Sets the attenuation level of the transmitted signal in 1
dB steps. The default (D3 - D0 = 0100) is for a transmit
level of -10 dBm0 on the line with the recommended
hybrid transmit gain. The total range is 16 dB.
Receive Gain
0
18 dB receive front end boost is not used.
Boost
1
Boost is in the path. This boost does not change
reference levels. It is used to extend dynamic range by
compensating for internally generated noise when
receiving weak signals. The receive level detect signal
and knowledge of the hybrid and transmit attenuator
setting will determine when boost should be enabled.
OH
0
Relay driver open.
1
Open drain driver pulling low.
Tri-state
0
TXCLK and RXCLK are driven.
TXCLK/RXCLK
1
TXCLK and RXCLK are tri-stated.
TXDALT
Special Register
Bit D3=1
Alternate TX data source (see Special Register).
18
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
SPECIAL REGISTER
SR
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
101
0
TXBAUD
CLOCK
RXUNDSCR
DATA
0
TXD
SOURCE
SIGNAL
QUALITY
LEVEL
SELECT 1
SIGNAL
QUALITY
LEVEL
SELECT 0
0
NAME
DESCRIPTION
BIT
D7, D4, D0
Not used at this time. Only write zeros to these bits.
D6
TXBAUD CLK
TXBAUD clock is the transmit baud-synchronous clock that can be used to
synchronize the input of arbitrary quad/di-bit patterns. The rising edge of
TXBAUD signals the latching of a baud-worth of data internally. Synchronous
data to be entered via the TXDALT bit, CR3 bit D7, should have data
transitions that start 1/2 bit period delayed from the TXBAUD clock edges.
D5
RXUNDSCR
Data
This bit outputs the data received before going to the descrambler.
This is useful for sending special unscrambled patterns that can be used for
signaling.
D3
TXD Source
This bit selects the transmit data source; either the TXD pin if zero or the
TXDALT if this bit is a one. The transmit pattern bits D7 and D6 in CR1
override either of these sources.
Signal Quality
Level Select
The signal quality indicator is a logical zero when the signal received is
acceptable for low error rate reception. It is determined by the value of the
mean squared error (MSE) calculated in the decisioning process when
compared to a given threshold. This threshold can be set to four levels of
error rate. The SQI bit will be low for good or average connections. As the
error rate crosses the threshold setting, the SQI bit will toggle at a 1.66 ms
rate. Toggling will continue until the error rate indicates that the data pump
has lost convergence and a retrain is required. At that point the SQI bit will be
a one constantly. The SQI bit and threshold selection are valid for QAM and
DPSK only and indicates typical error rate.
D2, D1
D2
D1
THRESHOLD VALUE
0
0
10-5
BER (default)
0
1
10-6
BER
1
0
10-4
BER
1
1
10
BER
-3
UNITS
NOTE: This register is "mapped" and is accessed by setting CR2 bit D6 to a one and addressing CR3. This
register provides functions to the 73K224BL user that are not necessary in normal communications.
Bits D7-D4 are read only, while D3-D0 are read/write. To return to normal CR3 access, CR2 bit D6
must be returned to a zero.
19
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
ID REGISTER
ID
D7
D6
D5
D4
D3
D2
D1
D0
ADDR
110
ID
ID
ID
ID
X
X
X
X
BIT
NAME
CONDITION
DESCRIPTION
D7, D6,
D7 D6 D5 D4
Indicates Device:
D5, D4
0
0
X
X
73K212L, 73K321L or 73K322L
0
1
X
X
73K221L or 73K302L
1
0
X
X
73K222L or 73K222BL
1
1
0
0
73K224L, 73K224BL
1
1
1
0
73K324L, 73K324BL
20
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
PARAMETER
RATING
VDD supply voltage
7V
Storage temperature
-65 to 150° C
Soldering temperature (10 s)
235° C
Applied voltage
-0.3 to VDD + 0.3 V
NOTE: All inputs and outputs are protected from static charge using built-in, industry standard protection
devices and all outputs are short-circuit protected.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
MIN
NOM
MAX
UNIT
VDD supply voltage
4.5
5
5.5
V
TA, operating free-air
-40
+85
C
-0.01
+0.01
%
Clock variation
CONDITION
(11.0592 MHz) crystal or external
clock
External components (Refer to application section for placement.)
VREF bypass capacitor
External to GND (Note 1)
0.1
µF
Bias setting resistor
Placed between VDD and ISET
pins
1.8
ISET bypass capacitor
ISET pin to GND
0.1
µF
VDD bypass capacitor 1
External to GND (Note 1)
0.1
µF
VDD bypass capacitor 2
External to GND (Note 1)
22
µF
XTL1 load capacitor
Depends on crystal characteristics
from pin to GND
40
pF
XTL2 load capacitor
Depends on crystal characteristics
from pin to GND
40
pF
Hybrid loading
see Figure 1
2
2.2
Ω
600
Ω
R1
600
Ω
R2
0.033
Ω
C1
µF
NOTE 1: Minimum for optimized system layout; may require higher values for noisy environments.
21
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DC ELECTRICAL CHARACTERISTICS
(TA = -40°C to 85°C, VDD = recommended range unless otherwise noted.)
PARAMETER
CONDITION
MIN
IDD, Supply Current
CLK = 11.0592 MHz
NOM
MAX
UNIT
ISET Resistor = 2 MΩ
IDD1, Active
Operating with crystal oscillator,
20
27
mA
IDD2, Idle
< 5 pF capacitive load on CLK pin
5
7
mA
0.8
V
2.0
VDD
V
3.0
VDD
V
100
µA
Digital Inputs
VIL, Input Low Voltage
VIH, Input High Voltage
All Inputs except Reset
XTL1, XTL2
Reset, XTL1, XTL2
IIH, Input High Current
VI = VDD
IIL, Input Low Current
VI = 0V
Reset Pull-down Current
Reset = VDD
-200
µA
2
50
µA
2.4
VDD
V
0.4
V
-50
µA
TBA
V
Digital Outputs
VOH, Output High Voltage
IO = IOH Min
IOUT = -0.4 mA
VOL, Output Low Voltage
IO = IOUT = 1.6 mA
RXD Tri-State Pull-up Curr.
RXD = GND
OH Output VOL
IOUT = 40 mA
-2
Capacitance
CLK
Maximum permitted load
25
pF
Input Capacitance
All digital inputs
10
pF
TXA1
NOTE: Parameters expressed in dBm0 refer
to signals at the telephone line, i.e., across
R2 in Figure 1.
R1
600Ω
The signals at TXA1 or TXA2 are each
≈ 8dB lower than at the line.
RXA
1:1
TXA2
The signal at RXA is ≈ 3 dB lower than at the
line.
R2
600Ω
C1
600Ω
(NOMINAL TELEPHONE
LINE IMPEDANCE)
FIGURE 1: ANALOG INTERFACE HYBRID LOADING
22
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
ELECTRICAL SPECIFICATIONS (continued)
DYNAMIC CHARACTERISTICS AND TIMING
(TA = -40°C to +85°C, VDD = recommended range unless otherwise noted.)
PARAMETER
CONDITION
MIN
Carrier suppression
Measured at TXA
35
Output Amplitude
TX Scrambled marks
NOM
MAX
UNIT
QAM/DPSK Modulator
-11.5
dB
-10
-9
dBm0
+0.20
%
-9
dBm0
-45
dB
ATT = 0100 (default)
FSK Modulator/Demodulator
Output Frequency Error
CLK = 11.0592 MHz
-0.31
Transmit Level
ATT = 0100 (default)
transmit dotting pattern
-11.5
TXA output distortion
All products through BPF
Output bias distortion
@ RXD
Dotting pattern measured at RXD
receive level -20 dBm, SNR 20 dB
-10
+10
%
Output jitter @ RXD
Integrated for 5 seconds
-15
+15
%
Sum of bias distortion and
output jitter
Integrated for 5 seconds
-17
+17
%
-9
dBm0
-40
dB
-0.03
+0.25
%
-10
Answer Tone Generator (2100 or 2225 Hz)
Output amplitude
ATT = 0100 (default level)
-11.5
-10
Not in V.21
Output Distortion
Distortion products in receive band
DTMF Generator
Not in V.21
Frequency accuracy
Output amplitude
Low band, ATT = 0100, DPSK mode
-10
-8
dBm0
Output amplitude
High band, ATT = 0100, DPSK mode
-8
-6
dBm0
Twist
High band to low band, DPSK mode
1
3
dB
Receiver Dynamic Range
Refer to performance curves
-43
-3
dBm0
Call Progress Detector
In call init mode
Detect level
460 Hz test signal
-34
0
dBm0
Reject level
460 Hz test signal
-40
dBm0
Delay time
-70 dBm0 to -30 dBm0 step
25
ms
Hold time
-30 dBm0 to -70 dBm0 step
25
ms
23
2
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DYNAMIC CHARACTERISTICS AND TIMING (continued)
PARAMETER
CONDITION
Carrier Detect
Receive gain = On for lower input level measurements
Threshold
All modes
Hysteresis
All modes
Delay Time
FSK
DPSK
QAM
Hold Time
FSK
DPSK
QAM
Answer Tone Detectors
MIN
NOM
-48
MAX
UNIT
-43
dBm0
2
70 dBm0 to -6 dBm0 Change at input
25
37
ms
70 dBm0 to -40 dBm0 Change at input
25
37
ms
-70 dBm0 to -6 dBm0 Change at input
7
17
ms
-70 dBm0 to -40 dBm0 Change at input
7
17
ms
-70 dBm0 to -6 dBm0 Change at input
25
37
ms
-70 dBm0 to -40 dBm0 Change at input
25
37
ms
-6 dBm0 to -70 dBm0 Change at input
25
37
ms
40 dBm0 to -70 dBm0 Change at input
15
30
ms
-6 dBm0 to -70 dBm0 Change at input
20
29
ms
-40 dBm0 to -70 dBm0 Change at input
14
21
ms
-6 dBm0 to -70 dBm0 Change at input
25
32
ms
-40 dBm0 to -70 dBm0 Change at input
18
28
ms
-48
-43
dBm0
DPSK Mode
Detect Level
Detect Time
Call init mode, 2100 or 2225 Hz
6
50
ms
Hold Time
Call init mode, 2100 or 2225 Hz
6
50
ms
Pattern Detectors
DPSK Mode
S1 Pattern
Delay Time
For signals from -6 to -40 dBm0,
10
55
ms
Hold Time
Demodulation mode
10
45
ms
Delay Time
For signals from -6 to -40 call init
10
45
ms
Hold Time
mode
10
45
ms
-22
-28
dBm0
7
ms
Unscrambled Mark
Receive Level Indicator
Detect On
Valid after Carrier Detect
DPSK Mode
1
24
4
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DYNAMIC CHARACTERISTICS AND TIMING (continued)
PARAMETER
CONDITION
MIN
1111-0000 (Default ATT=0100)
NOM
MAX
UNIT
-22
-6
dBm0
-0.15
+0.15
dB
1.5
mVrms
Transmit Attenuator
Range of Transmit Level
Step Accuracy
Clock Noise
TXA pins; 153.6 kHz
Carrier Offset
Capture Range
Originate or Answer
±5
Hz
Recovered Clock
Capture Range
% of frequency (originate or
answer)
-0.02
+0.02
%
Guard Tone Generator
Tone Accuracy
550 Hz
+1.2
1800 Hz
-0.8
%
Tone Level
550 Hz
-4.5
-3.0
-1.5
dB
(Below QAM/DPSK Output)
1800 Hz
-7.5
-6.1
-4.5
dB
Harmonic Distortion
550 Hz
-50
dB
(700 to 2900 Hz)
1800 Hz
-50
dB
25
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
DYNAMIC CHARACTERISTICS AND TIMING (continued)
PARAMETER
CONDITION
TIMING
(Refer to Timing Diagrams)
*
TAL
CS/Address setup before ALE Low
12
ns
CS
0
ns
Address hold after ALE Low
10
ns
TLC
ALE Low to RD/WR Low
10
ns
TCL
RD/WR Control to ALE High
0
ns
TRD
Data out from RD Low
0
TLL
ALE width
15
TRDF
Data float after RD High
TRW
RD width
50
ns
TWW
WR width
150
ns
TDW
Data setup before WR High
15
ns
TWD
Data hold after WR High
12
ns
TCKD
Data out after EXCLK Low
TCKW (serial mode)
WR after EXCLK Low
150
ns
TDCK (serial mode)
Data setup before EXCLK Low
150
ns
TAC (serial mode)
Address setup before control**
50
ns
TCA (serial mode)
Address hold after control**
50
ns
TWH (serial mode)
Data Hold after EXCLK
50
ns
CS
TLA
AD0-AD7
MIN
NOM
MAX
70
UNIT
ns
ns
50
200
ns
ns
* All timing parameters are targets and not guaranteed.
** Control for setup is the falling edge of RD or WR. Control for hold is the falling edge of RD or the rising
edge of WR.
NOTE: Asserting ALE, CS, and RD or WR concurrently can cause unintentional register accesses. When
using non-8031 compatible processors, care must be taken to prevent this from occurring when
designing the interface logic.
26
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
TIMING DIAGRAMS
TLL
ALE
TLC
RD
TRW
TCL
TLC
WR
TLA
TRD
TWW
TRDF
TWD
TAL
AD0-AD7
TDW
ADDRESS
READ DATA
ADDRESS
WRITE DATA
CS
FIGURE 2: Bus Timing Diagram (Parallel Control Mode)
EXCLK
RD
TAC
AD0-AD2
TCA
ADDRESS
TRD
D0
DATA
TRDF
TCKD
D1
D2
D3
D4
D5
D6
D7
FIGURE 3: Read Timing Diagram (Serial Control Mode)
EXCLK
TWW
WR
TCKW
AD0-AD2
ADDRESS
TDCK
DATA
TAC
D0
TWH
D1
D2
D3
D4
D5
D6
FIGURE 4: Write Timing Diagram (Serial Control Mode)
27
D7
TCA
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
address/data interface, and one for a serial
interface. The parallel version is intended for use
with
8039/48
or
8031/51
compatible
microcontrollers from Intel or many other
manufacturers. The serial interface mode can be
used with other microcontrollers or in applications
where only a limited number of port lines are
available or the application does not lend itself to a
multiplexed address/data interface. The parallel
versions may also be used in the serial mode, as
explained in the data sheet pin description.
APPLICATIONS INFORMATION
GENERAL CONSIDERATIONS
Figure 5 shows the basic circuit diagram for a
73K224BL modem integrated circuit designed to
be used in conjunction with a control processor, a
UART or RS-232 serial data interface, and a DAA
phone line interface to function as a typical
intelligent modem. The K-Series ICs interface
directly
with
Intel
8048
and
80C51
microprocessors for control and status monitoring
purposes. A typical DAA arrangement is shown in
Figure 5. This diagram is for reference only and
does not represent a production-ready modem
design.
In most applications the controller will monitor the
serial data for commands from the DTE and the
received data for break signals from the far end
modem. In this way, commands to the modem are
sent over the same line as the transmitted data. In
other applications the RS-232 interface handshake
lines are used for modem control.
The 73K224BL is available with two control
interface versions: one for a parallel multiplexed
RING DETECT
+5
TX DATA
RX DATA
+
2 MΩ
1 µF
1
2
3
11.0592
12 AD7
13 ALE
14 WR
15 RD
32
RXA
31
VREF
RESET 30
29
N/C
28
ISET
27
OH
26
RXCLK
25
RXD
24
TXD
23
CS
22
EXCLK
21
TXCLK
INT 20
19
N/C
18
TXA1
16 VDD
TXA2 17
4
5
6
7
CONTROL
INTERFACE
CLK
XTL1
XTL2
AD0
AD1
AD2
AD3
AD4
10 AD5
11 AD6
8
9
ADR/DATA BUS
µC ALE
µC WR
µC RD
+5
+
10 µF
GND
0.1 µF
RING
DETECTOR
8.2 K
0.1 µF
HOOK
RELAY
FUSE
600 Ω
+5
1
2
3
4
0.033 µF 600 Ω
1:1
TYP.
TRANSFORMER
0.1 µF
RXCLK
TXCLK
EXCLK
CHIP SELECT
FIGURE 5: Typical 73K224BL DAA Circuit
28
TRANSIENT
SUPPRESSOR
RJ - 11
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
APPLICATIONS INFORMATION (continued)
DESIGN CONSIDERATIONS
DIRECT ACCESS ARRANGEMENT (DAA)
Semiconductor's one-chip modem products
include all basic modem functions. This makes
these devices adaptable for use in a variety of
applications, and as easy to control as
conventional digital bus peripherals.
The DAA (Direct Access Arrangement) required
for the 73K224BL consists of an impedance
matching resistor, telecom coupling transformer,
and ring detection and fault protection circuitry.
Unlike digital logic circuitry, modem designs must
properly contend
with
precise frequency
tolerances and very low level analog signals, to
ensure acceptable performance. Using good
analog circuit design practices will generally result
in a sound design. Following are additional
recommendations which should be taken into
consideration when starting new designs.
The transformer specifications must comply with
the impedance of the country in which the modem
is being operated. Transformers designed
specifically for use with the telephone network
should be used. These may present a DC load to
the network themselves (a “wet” transformer) or
they may require AC coupling with a DC load
provided by additional devices (a “dry”
transformer). A dry transformer will generally
provide higher performance and smaller size than
a wet transformer. A wet transformer allows a
simpler design, but must not saturate with the
worst case DC current passing through it or
distortion and poor performance will result.
CRYSTAL OSCILLATOR
The K-Series crystal oscillator requires a parallel
mode (anti-resonant) crystal which operates at
11.0592 MHz. It is important that this frequency be
maintained to within ±0.01% accuracy.
In order for a parallel mode crystal to operate
correctly and to specification, it must have a
capacitor connected to the junction of each of the
crystal and internal inverter connections,
terminated to ground. The values of these
capacitors depend primarily on the crystal’s
characteristics, and to a lesser degree on the
internal inverter circuit. The values used affect the
accuracy and start up characteristics of the
oscillator.
The protection circuitry typically consists of a
transient suppression device and current limiter to
protect the user and the telephone network from
hazardous voltages that can be present under
fault conditions. The transient suppresser may be
a MOV (metal oxide varistor), Sidactor (Teccor
Electronics Inc.), spark gap device, or avalanche
diode. Some devices clamp the transient to their
specified break down voltage and others go into
low impedance crowbar state. The latter require
that the fault current cease before they can return
to their inactive state.
LAYOUT CONSIDERATIONS
Good analog/digital design rules must be used to
control system noise in order to obtain highest
performance in modem designs. The more digital
circuitry present on the PC board, the more this
attention to noise control is needed. The modem
should be treated as a high performance analog
device. A 22 µF electrolytic capacitor in parallel
with a 0.1 µF ceramic capacitor between VDD and
GND is recommended. Liberal use of ground
planes and larger traces on power and ground are
also highly favored. High speed digital circuits tend
to generate a significant amount of EMI (ElectroMagnetic Interference) which must be minimized
in order to meet regulatory agency limitations. To
accomplish this, high speed digital devices should
be locally bypassed, and the telephone line
interface and K-Series device should be located
Current limiting devices can consist of a resistor,
Raychem PolySwitch resettable fuse, or slow
blow fuse that can withstand the transient tests
without permanent damage or replacement.
Ring detection circuitry is not required by the FCC,
but may be required by the application. The ring
detector usually consists of an optoisolator,
capacitor, and resistor to present the proper AC
load to the network to meet the REN (Ring
Equivalency Number) regulations of FCC Part 68.
The K-Series Design Manual contains detailed
information on the design of a ring detect circuits
as well as the other topics concerning the DAA.
29
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
BER VS. S/N
close to each other near the area of the board
where the phone line connection is accessed. To
avoid problems, power supply and ground traces
should be routed separately to the analog and
digital functions on the board, and digital signals
should not be routed near low level or high
impedance analog traces. The analog and digital
grounds should only connect at one point near the
K-Series device ground pin to avoid ground loops.
The K-Series modem ICs should have both high
frequency and low frequency bypassing as close
to the package as possible.
This test measures the ability of the modem to
operate over noisy lines with a minimum of datatransfer errors. Since some noise is generated in
the best of dial-up lines, the modem must operate
with the lowest S/N ratio possible. Better modem
performance is indicated by test curves that are
closest to the BER axis. A narrow spread between
curves representing the four line parameters
indicates minimal variation in performance while
operating over a range of operating conditions.
Typically, a DPSK modem will exhibit better BER
performance test curves receiving in the low band
than in the high band.
MODEM PERFORMANCE
CHARACTERISTICS
BER VS. RECEIVE LEVEL
The curves presented here define modem IC
performance under a variety of line conditions
while inducing disturbances that are typical of
those encountered during data transmission on
public service telephone lines. Test data was
taken using an AEA Electronics’ “Autotest I”
modem test set and line simulator, operating
under computer control. All tests were run fullduplex, using a Concord Data Systems 224 as the
reference modem. A 511 pseudo-random-bit
pattern was used for each data point. Noise was
C-message weighted and all signal-to-noise (S/N)
ratios reflect total power measurements similar to
the CCITT V.56 measurement specification. The
individual tests are defined as follows.
This test measures the dynamic range of the
modem. Because signal levels vary widely over
dial-up lines, the widest possible dynamic range is
desirable. The minimum Bell specification calls for
36 dB of dynamic range. S/N ratios are held
constant at the indicated values while the receive
level is lowered from a very high to very low signal
levels. The width of the “bowl” of these curves,
taken at the BER point, is the measure of dynamic
range.
30
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
73K224BL BER vs S/N-DPSK LOW BAND
73K224BL BER vs S/N-DPSK HIGH BAND
10 -2
10 -2
HIGH BAND RECEIVE
-30 dBm
DPSK OPERATION
1200 BIT/S
LOW BAND RECEIVE
-30 dBm
DPSK OPERATION
1200 BIT/S
10 -3
10 -3
10
-4
10
-5
C1, 3002, FLAT
BIT ERROR RATE
BIT ERROR RATE
3002
10
-4
C1, C2, FLAT
10 -5
C2
10 -6
10 -6
4
6
8
10
12
14
4
16
6
8
10
12
16
73K224BL
BER VS S/N-QAM-HIGH BAND
73K224BL
BER VS S/N-QAM-LOW BAND
10 -2
10 -2
HIGH BAND RECEIVE
-30 dBm
QAM OPERATION
2400 BIT/S
HIGH BAND RECEIVE
-30 dBm
QAM OPERATION
2400 BIT/S
C1
C1
10 -3
10 -3
FLAT
BIT ERROR RATE
FLAT
BIT ERROR RATE
14
SIGNAL TO NOISE (dB)
SIGNAL TO NOISE (dB)
C2
10 -4
3002
10 -5
C2
10 -4
3002
10 -5
10 -6
10 -6
8
10
12
14
16
18
20
8
SIGNAL TO NOISE (dB)
10
12
14
16
SIGNAL TO NOISE (dB)
31
18
20
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
MECHANICAL SPECIFICATIONS
32-Lead PLCC
0.453 (11.51)
0.449 (11.40)
0.023
0.029
0.140 (3.56)
0.123 (3.12)
PIN NO. 1 IDENT.
0.595 (15.11)
0.585 (14.86)
0.553 (14.05)
0.549 (13.94)
0.095 (2.41)
0.078 (1.98)
0.050
0.013
0.021
0.300 REF
(7.62 REF)
0.430 (10.92)
0.390 (9.91)
0.026
0.032
0.400 REF
(10.16 REF)
0.530 (13.46)
0.490 (12.45)
0.495 (12.57)
0.485 (12.32)
44-Lead TQFP
16.0 BSC (0.630)
16.0 BSC (0.630)
INDEX
1
14.0 BSC (0.552)
1.35 (0.053)
1.45 (0.057)
0.09 (0.035)
0.20 (0.008)
0.42 (0.0165) Typ.
1.00 (0.0394) Typ.
32
0.60 (0.024) Typ.
0.045 (1.140)
0.020 (0.508)
73K224BL
V.22bis/V.22/V.21/Bell 212A/103
Single-Chip Modem w/ Integrated Hybrid
CAUTION: Use handling procedures necessary for
a static sensitive component.
PACKAGE PIN DESIGNATIONS
XTAL1
CLK
GND
RXA
VREF
4
3
2
1
32
31
RESET
XTAL2
(Top View)
AD2
7
27
OH
AD3
8
26
RXCLK
AD4
9
25
RXD
AD5
10
24
TXD
AD6
11
23
CS
DATA/AD7
12
22
EXCLK
ALE
13
TXCLK
14
15
16
17
18
19
21
20
INT
ISET
N/C
28
TXA1
6
TXA2
AD1
VDD
30
29
RD
5
WR
AD0
N/C
32-Lead PLCC
73K224BL-IH
44-Lead TQFP
73K224BL-IGT
ORDERING INFORMATION
PART DESCRIPTION
ORDER NUMBER
PACKAGING MARK
73K224BL
32-Lead PLCC
73K224BL-IH
73K224BL-IH
73K224BL
44-Lead TQFP
73K224BL-IGT
73L224BL-IGT
No responsibility is assumed by TDK Semiconductor Corporation for use of this product nor for any infringements of patents and
trademarks or other rights of third parties resulting from its use. No license is granted under any patents, patent rights or trademarks of
TDK Semiconductor Corporation, and the company reserves the right to make changes in specifications at any time without notice.
Accordingly, the reader is cautioned to verify that the data sheet is current before placing orders.
TDK Semiconductor Corporation, 2642 Michelle Dr., Tustin, CA 92780-7019, (714) 508-8800, FAX: (714) 508-8877
Protected by the following Patents (4,691,172) (4,777,453)
© 1996 - 2000 TDK Semiconductor Corporation
04/24/00 - rev. E
33