CMLMICRO CMX605

CMX605
Digital Line to
POTS Interface
D/605/6 July 2001
Provisional Issue
Features
Applications
• Pre-Programmed Tone Generators
• Digital Line to POTS Interface
• Fully Integrated DTMF Decoder/Encoder
• Subscriber Terminal Adapters
• SPM Generator
• Wireless Local Loop
• Simple Serial Control Interface
• Computer Telephony Integration
• 3.58MHz Xtal/Clock
• Telephone/Radio Patch Systems
• V23/Bell 202 FSK Generator
• Pair Gain Systems
• Digital Ringing Voltage Generator
• Billing/SPM Systems
1.1
Brief Description
The CMX605 is an integrated telecom tone generator and DTMF encoder/decoder designed for ISDN
interfaces, Wireless Local Loop and Analogue to Digital Phone Conversion systems. The tone generator
covers an extensive range of pre-programmed tones used in analogue phone systems (POTS). Three
outputs are provided: ‘Ringing signals’, ‘In-band tones or FSK data’, and ‘12kHz/16kHz Metering pulses’.
Simple software control facilitates the interface to a wide range of commonly used µCs and SLICs,
enabling a comprehensive analogue telephone line presentation.
The DTMF encoder/decoder presents the digital line interface with DTMF dialling information received
from the telephone user and generates the appropriate DTMF tones for the POTS interface. DTMF tone
pairs can be encoded along with each tone singly or with other dual tone signals, such as those used in
CIDCW systems and ‘On Hook’ signalling systems.
Other tone standards supported are: Fax and Modem ‘answer’ and ‘originate’, ITU (CCITT) ‘R1’ and ‘R2’
signals, and sufficient tones for simple melody generation. Communication to and from the host
µController is performed by a ‘C-BUS’ serial interface, which is compatible with the ‘SPI’ interface.
 2001 Consumer Microcircuits Limited
Digital Line to POTS Interface
CMX605
CONTENTS
Section
Page
1.1
Brief Description ............................................................................ 1
1.2
Block Diagram................................................................................. 3
1.3
Signal List......................................................................................... 4
1.4
External Components ................................................................... 6
1.5
General Description ...................................................................... 7
1.5.1
1.5.2
1.5.3
1.5.4
1.5.5
1.5.6
1.5.7
1.5.8
1.5.9
1.6
Application Notes ........................................................................ 15
1.6.1
1.6.2
1.7
Xtal Osc and Clock Dividers................................................... 7
Uncommitted Amplifier........................................................... 7
Tone/FSK Encoder and Tone Encoder .................................. 7
SPM Generator ...................................................................... 10
Transmit Operator................................................................. 10
Tx UART ................................................................................ 10
DTMF Tone Decoder ............................................................. 12
‘C-BUS’ Interface................................................................... 13
‘C-BUS’ Registers ................................................................. 14
Telecom Tones ....................................................................... 15
C-BUS Timing......................................................................... 19
Performance Specification ....................................................... 22
1.7.1
1.7.2
Electrical Performance.......................................................... 22
Packaging.............................................................................. 26
 2001 Consumer Microcircuits Limited
2
D/605/6
Digital Line to POTS Interface
1.2
CMX605
Block Diagram
Figure 1 Block Diagram
 2001 Consumer Microcircuits Limited
3
D/605/6
Digital Line to POTS Interface
1.3
CMX605
Signal List
CMX605
D4/P3
Signal
Description
Pin No.
Name
Type
1
XTALN
O/P
The output of the on-chip Xtal oscillator
inverter.
2
XTAL/CLOCK
I/P
The input to the oscillator inverter from the
Xtal circuit or external clock source.
3
SERCK
I/P
The ‘C-BUS’ serial clock input from the host
µC. See section 1.5.8
4
COMDATA
I/P
The ‘C-BUS’ serial data input from the host
µC.
5
REPDATA
T/S
A 3-state ‘C-BUS’ serial data output to the
host µC. This output is high impedance when
not sending data to the host µC.
6
CSN
I/P
The ‘C-BUS’ transfer control input provided by
the host µC.
7
IRQN
O/P
A ‘wire-ORable’ output for connection to a
host µC Interrupt Request input. This output is
pulled down to VSS when active and is high
impedance when inactive. An external pullup
resistor is required.
8
VSS
Power
9
TONEFSK
O/P
The sinewave output of the Tones and FSK
signal generators.
10
SPM
O/P
The sinewave output of the SPM signal
generator.
 2001 Consumer Microcircuits Limited
The negative supply rail (ground).
4
D/605/6
Digital Line to POTS Interface
CMX605
Signal
CMX605
D4/P3
Description
Pin No.
Name
Type
11
VBIAS
O/P
An internally generated bias voltage of VDD/2,
except when the device has been reset, VBIAS
will discharge to VSS. It should be decoupled to
VSS by a capacitor mounted close to the device
pins.
12
RXIN
I/P
The input to the DTMF decoder, internally
biased at VDD/2. It should be ac coupled.
13
OPNIN
I/P
The inverting input to the uncommitted
amplifier.
14
OPOUT
O/P
The output of the uncommitted amplifier.
15
RING
O/P
The squarewave output of the Ringing Signal
generator.
16
VDD
Power
The positive supply rail. Levels and thresholds
within the device are proportional to this
voltage. It should be decoupled to VSS by a
capacitor mounted close to the device pins.
Notes:
I/P
O/P
T/S
=
=
=
Input
Output
3-state Output
This device is capable of detecting and decoding small amplitude signals. To achieve this VDD
and VBIAS decoupling and protecting the receive path from extraneous in-band signals are very
important. It is recommended that the printed circuit board is laid out with a ground plane in the
CMX605 area to provide a low impedance connection between the VSS pin and the VDD and
VBIAS decoupling capacitors.
 2001 Consumer Microcircuits Limited
5
D/605/6
Digital Line to POTS Interface
1.4
CMX605
External Components
Figure 2 Recommended External Components
R1
X1
C1, C2
C3
C4, C5
100kΩ
3.579545 MHz
18pF
0.1µF
1.0µF
Resistors ±5%, capacitors ±10% unless otherwise stated.
 2001 Consumer Microcircuits Limited
6
D/605/6
Digital Line to POTS Interface
1.5
CMX605
General Description
The CMX605 is a telecom tone generator and DTMF tone encoder/decoder. It has separate output ports
for the three different classes of signals encoded. These include Ringing signal, In-band tones or FSK
data at 1200bps and High frequency metering pulses (SPM tones). It has a transmit level attenuator for
In-band tones or FSK data and an envelope control for SPM tones. It also has an uncommitted amplifier
and uses the industry standard 3.58MHz Xtal for its oscillator. These functions are controlled over a ‘CBUS‘ serial µC interface, which also carries the transmit FSK data and the DTMF decoded data.
The CMX605 should initially be reset by issuing a ‘C-BUS’ RESET command. Individual functions may
be disabled or enabled by the use of bits 5, 6 and 7 in the SETUP Register. See Section 1.5.9.
Approximately 50ms should be allowed for the Tx dc level to settle at VBIAS before enabling the Tx
functions (set bit 6 of the MODE Register to ‘1’) after the CMX605 has been reset.
1.5.1
Xtal Osc and Clock Dividers
Frequency and timing accuracy of the CMX605 is determined by a 3.579545MHz clock present at the
XTAL/CLOCK pin. This may be generated by the on-chip oscillator inverter using the external
components C1, C2 and X1 of Figure 2, or may be supplied from an external source to the XTAL/CLOCK
input. If the clock is supplied from an external source, C1, C2 and X1 should not be fitted.
If the clock is provided by an external source which is not always running, then the CMX605 should be
reset when the clock is not available. Resetting the CMX605 will also turn off the on-chip oscillator.
Failure to reset the device may cause a rise in the supply current drawn by the CMX605.
1.5.2
Uncommitted Amplifier
This amplifier, with suitable external components, can be used either for adjusting the received signal to
the correct amplitude for the DTMF decoder or for adjusting the transmit signal level (for the line hybrid).
1.5.3
Tone/FSK Encoder and Tone Encoder
When bit 5 of the MODE Register is set to ‘1’ then these blocks generate FSK signals as determined by
bit 0 of the SETUP Register and the Tx data bits from the UART block, as shown in the table below:
SETUP Register
Bit 0
0
1
Tone/FSK Generator
V23 1200bps FSK
Bell 202 1200bps FSK
FSK Signal Frequency
‘0’ (Space)
2100Hz
2200Hz
FSK Signal Frequency
‘1’ (Mark)
1300Hz
1200Hz
When bit 5 of the MODE Register is set to ‘0’, these blocks generate single or dual tones from the range
shown in the tables on the following pages. Bit 6 of the MODE Register is then used to enable or disable
the block’s output to the Tx Signal Control, RING and TONEFSK outputs. There are four tone fields
addressed by bits 0 and 1 of the MODE Register.
 2001 Consumer Microcircuits Limited
7
D/605/6
Digital Line to POTS Interface
CMX605
Tone Field 0, MODE Register bit 1 and bit 0 = ‘0’ and ‘0’ respectively.
TX TONES Register Bits
D7
D6
D5
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
4-7
D4
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Frequency
(Hz)
0 = OFF
252.4
268.7
285.3
315.5
330.5
375.2
404.3
468.0
495.8
520.6
548.0
562.8
578.4
595.0
612.5
TX TONES Register Bits
D3
D2
D1
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
0-3
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Frequency
(Hz)
0 = OFF
* 17.1
* 20.5
* 24.9
* 34.1
* 41.0
* 51.2
262.9
293.6
348.2
392.6
1600
1633
1827
587.2
NOTE: * These outputs are routed to the RING digital output instead of the TONEFSK output. Any
single tone output level at TONEFSK output is 0dBm.
Tone Field 1, MODE Register bit 1 and bit 0 = ‘0’ and ‘1’ respectively
TX TONES Register Bits 4-7
D7
D6
D5
D4
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
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
 2001 Consumer Microcircuits Limited
Frequency
(Hz)
0 = OFF
120
150
154
250
300
350
360
367
375
380
383
400
450
475
480
TX TONES Register Bits 0-3
D3
D2
D1
D0
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
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
8
Frequency
(Hz)
0 = OFF
330
416
420
425
433
440
450
460
480
500
600
620
720
930
-
D/605/6
Digital Line to POTS Interface
CMX605
Tone Field 2, MODE Register bit 1 and bit 0 = ‘1’ and ‘0’ respectively
TX TONES Register Bits
D7
D6
D5
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
4-7
D4
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Frequency
(Hz)
0 = OFF
700
900
1100
1300
1500
1700
950
1400
1800
2130
697
770
852
941
TX TONES Register Bits
D3
D2
D1
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
0-3
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Frequency
(Hz)
0 = OFF
700
900
1100
1300
1500
1700
2100
2225
2750
1209
1336
1477
1633
0-3
D0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Frequency
(Hz)
0 = OFF
540
660
780
900
1020
1140
1380
1500
1620
1740
1860
1980
-
Tone Field 3, MODE Register bit 1 and bit 0 = ‘1’ and ‘1’ respectively
TX TONES Register Bits
D7
D6
D5
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
4-7
D4
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
 2001 Consumer Microcircuits Limited
Frequency
(Hz)
0 = OFF
540
660
780
900
1020
1140
1380
1500
1620
1740
1860
1980
-
TX TONES Register Bits
D3
D2
D1
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
9
D/605/6
Digital Line to POTS Interface
1.5.4
CMX605
SPM Generator
This block operates independently and has its own output pin. It can transmit 12kHz or 16kHz and is
controlled by bit 4 of the SETUP Register. Bit 7 of the MODE Register is used to enable or disable this
block. The signal has a rise and fall time each of about 4.5ms. The SPM signal rises from the bias level
to 0dBm in 16 steps of »2dB magnitude, and falls from 0dBm to bias level in 16 steps of »2dB
magnitude.
1.5.5
Transmit Signal Control
This block adjusts the amplitude of the FSK transmit signal output level, the level skew between DTMF
tones and the signal routing to the output ports.
Output signal levels are proportional to VDD. The nominal output signal levels (at 0dB attenuation and
VDD = 5.0V) are:
Single Tone
Dual Tone (per tone)
DTMF High Frequency Tone
DTMF Low Frequency Tone
FSK Signal
0dBm
-3dBm
-3dBm
-5dBm
0dBm
The RING signal is digital: a square wave with amplitude of ≈ VDD peak to peak. When the RING signal
is not selected, the RING output pin is connected to VSS.
The level attenuator provides for level adjustment from 0dB to -14dB in -2dB steps. The typical level is
determined by bits 2 to 4 of the MODE Register as shown in the table below:
MODE Register
Bit 4
Bit 3
0
0
0
0
0
1
0
1
1
0
1
0
1
1
1
1
1.5.6
Bit 2
0
1
0
1
0
1
0
1
Signal Level Adjustment
(dB)
0
-2
-4
-6
-8
-10
-12
-14
Tx UART
This block connects the µC, via the ‘C-BUS’ interface, to the FSK Encoder.
The block can be programmed to convert transmit data from 8-bit bytes to asynchronous data characters
by adding Start and Stop bits. The transmit data is then passed to the FSK Encoder.
Data to be transmitted should be loaded by the µC into the TX DATA Register when the Tx Data Ready
bit (bit 6) of the STATUS Register goes high. It will then be treated by the Tx UART block in one of two
ways, depending on the setting of bit 1 of the SETUP Register:
If bit 1 of the SETUP Register is ‘0’ (Tx Sync mode) then the 8 bits from the TX DATA Register
will be transmitted sequentially at 1200bps, lsb (D0) first.
If bit 1 of the SETUP Register is ‘1’ (Tx Async mode) then bits will be transmitted as
asynchronous data characters at 1200 bps according to the following format:
 2001 Consumer Microcircuits Limited
10
D/605/6
Digital Line to POTS Interface
CMX605
One Start bit (Space)
Eight Data bits (D0-D7) from the TX DATA Register, with the lsb (D0) transmitted first
One Stop bit (Mark)
Failure to load the TX DATA Register with a new value when required will result in bit 7 (Tx Data
Underflow) of the STATUS Register being set to ‘1’. If the ‘Tx Async’ mode of operation is selected then
a continuous Mark (‘1’) signal will be transmitted until a new value is loaded into TX DATA. If the ‘Tx
Sync’ mode is selected then the byte already in the TX DATA Register will be re-transmitted.
Figure 3a Transmit UART Function (Async)
Figure 3b Transmit UART Function (Sync)
 2001 Consumer Microcircuits Limited
11
D/605/6
Digital Line to POTS Interface
1.5.7
CMX605
DTMF Tone Decoder
This block is enabled or disabled by bit 5 of the SETUP register. If disabled, bit 0 to bit 5 of the STATUS
Register are set to ‘0’ and no interrupts are generated. When enabled (set to ‘1’), a status change of the
decoder will generate an interrupt and bit 5 of the STATUS Register will be set to ‘1’. The validity of the
data is indicated by bit 4 of the STATUS Register. The decode truth table is shown below:
STATUS Register Bits 0 - 3
Bit 3
Bit 2
Bit 1
(D3)
(D2)
(D1)
0
0
0
0
0
0
0
0
1
0
0
1
0
1
0
0
1
0
0
1
1
0
1
1
1
0
0
1
0
0
1
0
1
1
0
1
1
1
0
1
1
0
1
1
1
1
1
1
Bit 0
(D0)
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
DTMF Tone
Lower Frequency
(Hz)
941
697
697
697
770
770
770
852
852
852
941
941
941
697
770
852
Pairs
Upper Frequency
(Hz)
1633
1209
1336
1477
1209
1336
1477
1209
1336
1477
1336
1209
1477
1633
1633
1633
Keypad
Legend
D
1
2
3
4
5
6
7
8
9
0
*
#
A
B
C
A status change of the decoder and the generation of an interrupt will occur both when a tone is first
decoded and also when a tone, which was previously present, is no longer decoded. In the latter case,
Bit 4 of the STATUS Register will be set to “0” to indicate that no tone was detected.
 2001 Consumer Microcircuits Limited
12
D/605/6
Digital Line to POTS Interface
1.5.8
CMX605
‘C-BUS’ Interface
This block provides for the transfer of data and control or status information between the CMX605’s
internal registers and the µC over the ‘C-BUS’ serial bus. Each transaction consists of a single Register
Address byte sent from the µC which may be followed by a single data byte sent from the µC to be
written into one of the CMX605’s Write Only Registers, or a single byte of data read out from one of the
CMX605’s Read Only Registers, as illustrated in Figure 4.
Data sent from the µC on the Command Data (COMDATA) line is clocked into the CMX605 on the rising
edge of the Serial Clock (SERCK) input. Reply Data (REPDATA) sent from the CMX605 to the µC is
valid when the Serial Clock is high. The interface is compatible with the most common µC serial
interfaces such as SCI, SPI and Microwire, and may also be easily implemented with general purpose µC
I/O pins controlled by a simple software routine. See Figure 8 for detailed ‘C-BUS’ timing requirements.
Figure 4 ‘C-BUS’ Transactions
 2001 Consumer Microcircuits Limited
13
D/605/6
Digital Line to POTS Interface
1.5.9
CMX605
‘C-BUS’ Registers
Write Only Registers
Addr.
$01
$D0
Register
RESET
SETUP
$D1
MODE
$D3
TX
DATA
TX
TONES
$D4
7
Command Data Byte (Bits 7 - 0)
5
4
3
6
2
1
0
N/A
Uncommitted
Amplifier
0 = Disable
1 = Enable
N/A
Tx Enable:
0 = Disable
1 = Enable
N/A
DTMF Rx:
0 = Disable
1 = Enable
N/A
SPM:
0 = 12kHz
1 = 16kHz
N/A
Reserved
set to 0
N/A
Reserved
set to 0
SPM O/P:
0 = Disable
1 = Enable
D7
Tone/FSK:
0 = Disable
1 = Enable
D6
Tone/FSK:
0 = Tone
1 = FSK
D5
Tx Level:
Tx Level:
Tx Level:
(msb)
D4
D3
(lsb)
D2
N/A
N/A
FSK mode: FSK
0 = Sync
mode:
1 = Async 0 = V23
1 = Bell
202
Tone
Tone
Fields:
Fields:
(msb)
(lsb)
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
Read Only Registers
Addr. Register
$DF STATUS
7
6
5
FSK Mode:
FSK Tx Data
Underflow
FSK Mode:
FSK Tx
Data Ready
DTMF Rx:
Status
Change
Reply Data Byte (Bits 7 - 0)
4
3
DTMF Rx:
1 = Detected
0 = Notone
Timer timed
out
DTMF:
Rx Data
(D3) (msb)
2
DTMF:
Rx Data
(D2)
1
DTMF:
Rx Data
(D1)
0
DTMF:
Rx Data
(D0) (lsb)
Notes:
1. Accessing the RESET Register over the ‘C-BUS’ clears all of the bits in the SETUP, MODE,
TX DATA, TX TONES and STATUS registers. This will initialise the device and put it into zeropower mode. Please allow 50ms for the oscillator, VBIAS and internal circuits to stabilize when
coming out of zero-power mode.
Note that this is a single-byte ‘C-BUS’ transaction consisting solely of the address byte value $01.
2. If any of bits 5, 6 or 7 of the STATUS Register is ‘1’ then the IRQN output will be pulled low.
3. Reading the STATUS Register clears the IRQN output and also clears bit 5 of the STATUS
Register, if set. Bits 6 and 7 of the STATUS Register are cleared on writing to the TX DATA
Register.
 2001 Consumer Microcircuits Limited
14
D/605/6
Digital Line to POTS Interface
1.6
CMX605
Application Notes
When using the Tone/FSK bit (bit 6) of the MODE Register, each tone starts from VBIAS, and
returns to VBIAS before ending:
Figure 5 Tone Starting and Stopping
When switching between tones in the same column (bits 4 - 7 or bits 0 - 3) of the TX TONES
Register), the transition will be phase continuous. However, switching to the “OFF” state will
immediately take the output of that tone generator to VBIAS.
Figure 6 Tone Changing
TX TONES Register decodes which do not have a frequency allocated are indicated by “-“ in the
Tone Field tables. These values should not be used.
1.6.1
Telecom Tones
The following tables give the hex codes to be programmed into the particular tone field location
for various telecommunications systems applications. The tables are not exhaustive, but list the
more commonly used tones.
Ringing Signals
(f ± 2.5%)
(Hz)
Off
16.7
20
25
35
40
50
 2001 Consumer Microcircuits Limited
Field 0
(Hex)
$00
$01
$02
$03
$04
$05
$06
15
D/605/6
Digital Line to POTS Interface
CMX605
On Hook ‘CPE Alert Tones
Single Tone
(Hz)
375.2
404.3
468
495.8
520.6
548
562.8
578.4
1633
Dual Tone
Field 0
(Hex)
$60
$70
$80
$90
$A0
$B0
$C0
$D0
$0D
(Hz)
375.2+1827
404.3+1827
468+1827
495.8+1827
520.6+1827
548+1827
562.8+1827
578.4+1827
Field 0
(Hex)
$6E
$7E
$8E
$9E
$AE
$BE
$CE
$DE
NYNEX (MRAA) - AMR Alert Tones (Single Tone)
Group A
(Hz)
252.4
268.7
285.3
315.5
330.5
375.2
Group B
Field 0
(Hex)
$10
$20
$30
$40
$50
$60
(Hz)
468
495.8
520.6
562.8
595
612.5
Field 0
(Hex)
$80
$90
$A0
$C0
$E0
$F0
Single Frequency Call Progress Tones
(Hz)
Off
120
150
154
250
300
350
400
425
440
450
480
500
600
620
 2001 Consumer Microcircuits Limited
Field 1
(Hex)
$00
$10
$20
$30
$40
$50
$60
$C0
$04
$06
$07
$09
$0A
$0B
$0C
16
D/605/6
Digital Line to POTS Interface
CMX605
Dual Frequency Call Progress Tones
Additive Mixing
Multiplicative
Mixing
Field 1
(Hex)
$00
$66
$F6
$FC
$C4
$C7
$D4
$F4
$1C
$27
(Hz)
Off
350+440
440+480
480+620
400+425
400+450
425+450
425+480
120+620
150+450
(Hz)
Field 1
(Hex)
400*16.2
400*20
400*25
400*33
400*40
400*50
450*25
600*120
$B2
$A3
$94
$85
$76
$67
$E4
$FD
Dual Tone Multi Frequency Generation
Field 2
(Hex)
$00
$FF
$CC
$CD
$CE
$DC
$DD
$DE
$EC
$ED
$EE
$FD
$FC
$FE
$CF
$DF
$EF
(Hz)
Off
941+1633
697+1209
697+1336
697+1477
770+1209
770+1336
770+1477
852+1209
852+1336
852+1477
941+1336
941+1209
941+1477
697+1633
770+1633
852+1633
Special Information Tones, Fax and Modem Tones and Customer Premises Alert Tones
(Hz)
Off
950
1100
1300
1400
1800
2100
2225
2130+2750
Field 2
(Hex)
$00
$80
$30
$40
$90
$A0
$08
$09
$BB
 2001 Consumer Microcircuits Limited
17
D/605/6
Digital Line to POTS Interface
CMX605
CCITT ‘R1’ Signalling Tones
(Hz)
700+900
700+1100
900+1100
700+1300
900+1300
1100+1300
700+1500
900+1500
1100+1500
1300+1500
700+1700
900+1700
1100+1700
1300+1700
1500+1700
Field 2
(Hex)
$12
$13
$23
$14
$24
$34
$15
$25
$35
$45
$16
$26
$36
$46
$56
CCITT ‘R2’ Signalling Tones
Forward mode
(Hz)
Off
1380+1500
1380+1620
1500+1620
1380+1740
1500+1740
1620+1740
1380+1860
1500+1860
1620+1860
1740+1860
1380+1980
1500+1980
1620+1980
1740+1980
1860+1980
 2001 Consumer Microcircuits Limited
Backward mode
Field 3
(Hex)
$00
$89
$8A
$9A
$8B
$9B
$AB
$8C
$9C
$AC
$BC
$8D
$9D
$AD
$BD
$CD
(Hz)
Off
1140+1020
1140+900
1020+900
1140+780
1020+780
900+780
1140+660
1020+660
900+660
780+660
1140+540
1020+540
900+540
780+540
660+540
18
Field 3
(Hex)
$00
$65
$64
$54
$63
$53
$43
$62
$52
$42
$32
$61
$51
$41
$31
$21
D/605/6
Digital Line to POTS Interface
1.6.2
CMX605
C-BUS Timing
The relationship between bytes loaded onto the C-BUS and the transmission of FSK bytes is
shown diagrammatically in Figures 7a, 7b and 7c.
There are many ways in which the C-BUS can be used to program a device and three
suggestions (one for asynchronous FSK - Figure 7a - and two for synchronous FSK - Figures 7b
and 7c) are shown here, together with typical timings. Please note that the C-BUS timing is not
shown to the same scale as the FSK output (it has been magnified by at least 20 times to make it
visible on the same scale).
Figure 7a ASYNC mode after GENERAL RESET
 2001 Consumer Microcircuits Limited
19
D/605/6
Digital Line to POTS Interface
CMX605
Figure 7b SYNC mode after GENERAL RESET
 2001 Consumer Microcircuits Limited
20
D/605/6
Digital Line to POTS Interface
CMX605
Figure 7c SYNC mode after GENERAL RESET
(using alternative order of commands)
 2001 Consumer Microcircuits Limited
21
D/605/6
Digital Line to POTS Interface
1.7
Performance Specification
1.7.1
Electrical Performance
CMX605
1.7.1.1 Absolute Maximum Ratings
Exceeding these maximum ratings can result in damage to the device.
Supply (VDD - VSS)
Voltage on any pin to VSS
Current into or out of VDD and VSS pins
Current into or out of any other pin
D4/P3 Package
Total Allowable Power Dissipation at Tamb = 25°C
... Derating
Storage Temperature
Operating Temperature
Min.
-0.3
-0.3
-50
-20
Max.
7.0
VDD + 0.3
+50
+20
Unit
V
V
mA
mA
Min.
Max.
800
13
+125
+85
Unit
mW
mW/°C
°C
°C
Max.
5.5
+85
3.583125
Unit
V
°C
MHz
-55
-40
1.7.1.2 Operating Limits
Correct operation of the device outside these limits is not implied.
Notes
Supply (VDD - VSS)
Operating Temperature
Xtal Frequency
Notes:
1
Min.
2.7
-40
3.575965
1. A Xtal frequency of 3.579545MHz ±0.1% is required for correct operation.
 2001 Consumer Microcircuits Limited
22
D/605/6
Digital Line to POTS Interface
CMX605
1.7.1.3 Operating Characteristics
For the following conditions unless otherwise specified:
VDD = 2.7V at Tamb = 25°C and VDD = 3.0V to 5.5V at Tamb = -40 to +85°C,
Xtal Frequency = 3.579545MHz ± 0.1%
0dBm corresponds to 775mVrms.
DC Parameters
Notes
Min.
Typ.
1
1.0
IDD Zero-power mode
OpAmp only Enabled (VDD = 5.0V)
1
1.0
DTMF Rx only, VDD = 5.0V
1
2.0
Tx (tones, SPM) only, VDD = 5.0V
1
3.5
All Enabled, VDD = 5.0V
1
6.6
OpAmp only Enabled (VDD = 3.3V)
1
0.75
DTMF Rx only, VDD = 3.3V
1
1.2
Tx (tones, SPM) only, VDD = 3.3V
1
2.0
All Enabled, VDD = 3.3V
1
3.5
Logic ‘1’ Input Level
3
70%
Logic ‘0’ Input Level
3
Logic Input Leakage Current (Vin = 0 to VDD),
3
-1.0
(excluding XTAL/CLOCK input)
Output Logic ‘1’ Level (IOH = 360µA)
VDD-0.4
Output Logic ‘0’ Level (IOL = 360µA)
IRQN O/P ‘Off State Current (VOUT = VDD)
FSK Encoder and Tx UART
Level at TONEFSK pin
Twist (Mark level WRT Space level)
Tx 1200bits/sec (V23 mode)
Baud Rate (set by UART and Xtal frequency)
Mark (Logical 1) Frequency
Space (Logical 0) Frequency
Tx 1200bits/sec (Bell 202 mode)
Baud Rate (set by UART and Xtal frequency)
Mark (Logical 1) Frequency
Space (Logical 0) Frequency
TONEFSK Signal Level
Level at TONEFSK pin for:
Single tone
Dual tone (per tone)
DTMF High Frequency Group
DTMF Low Frequency Group
Output Impedance
Tone frequency resolution
Tone output distortion
Notes:
Max.
10.0
3.2
5.5
10.0
2.5
3.0
5.5
30%
+1.0
Unit
µA
mA
mA
mA
mA
mA
mA
mA
mA
VDD
VDD
µA
0.4
1.0
V
V
µA
Notes
Min.
Typ.
Max.
Unit
4
-1.0
-2.0
0.0
0
1.0
+2.0
dBm
dB
1194
1297
2097
1200
1300
2100
1206
1303
2103
Baud
Hz
Hz
1194
1197
2197
1200
1200
2200
1206
1203
2203
Baud
Hz
Hz
Notes
Min.
Typ.
Max.
Unit
4
4
4
4
-1.0
-4.0
-4.0
-6.0
-2.0
-
0
-3.0
-3.0
-5.0
10.0
0.8
1.0
-2.0
-2.0
-4.0
2.0
-
dBm
dBm
dBm
dBm
kΩ
Hz
%
5
1. At 25°C, not including any current drawn from the CMX605 pins by external circuitry
other than X1, C1 and C2.
2. At nominal signal frequencies and without skew.
3. Excluding XTAL/CLOCK pin.
4. At VDD = 5.0V, load resistance greater than 40kΩ, signal levels are proportional to VDD.
5. Frequency above 300Hz.
6. SPM has a soft rise and fall time of about 4.5ms. The level changes between VBIAS and
0dBm in 2dB steps, 16 steps per rise and fall. When SPM is disabled, an extra 4.5ms
falling tail end of signal should be taken into consideration.
 2001 Consumer Microcircuits Limited
23
D/605/6
Digital Line to POTS Interface
CMX605
DTMF Decoder
Valid input signal levels
(each tone of composite signal)
Not decode level
(either tone of composite signal)
Twist = High Tone/Low Tone
Frequency Detect Bandwidth
Input Impedance for RXIN (at 100Hz)
Dial Tone Tolerance
Noise Tolerance
Tone Response time
Tone De-response time
Tone burst detected
Tone burst ignored
Pause length detected
Pause length ignored
Notes
Min.
Typ.
Max.
Unit
4
-29.0
-
-2.0
dBm
4
-9.0
±1.8
40.0
40.0
-
0.5
-14
20.0
-
-40.0
10.0
±4.5
0
40.0
45.0
20.0
dBm
dB
%
MΩ
dB
dB
ms
ms
ms
ms
ms
ms
7
7,8
2
2
2
2
2
2
SPM Signal Level
Notes
Min.
Typ.
Max.
Unit
Level at SPM pin
4, 6
4, 6, 10
-1.5
-1.0
-14.0
-
0
0
1.2
10.0
1.0
0.5
14.0
-
dBm
dB
Hz
%
kΩ
Min.
Typ.
Max.
Unit
10.0
-
60.0
5.0
10.0
-
dB
MHz
MΩ
kΩ
Min.
Typ.
Max.
Unit
-
50
-
ms
Notes
Min.
Typ.
Max.
Unit
9
9
100
100
20.0
1.0
-
-
ns
ns
MΩ
dB
Tone frequency accuracy
Tone output distortion
Output Impedance
5
Uncommitted Amplifier
Notes
Open Loop Gain (I/P = 1mVrms at 100Hz)
Unity Gain Bandwidth
Input Impedance (at 100Hz)
Output Impedance (Open Loop)
Power-Up Timing
Notes
Device reset to reliable signal at
OPOUT, RING, SPM or TONEFSK
output pins
XTAL/CLOCK Input
'High' Pulse Width
'Low' Pulse Width
Input Impedance (at 100Hz)
Gain (I/P = 1mVrms at 100Hz)
Notes:
7.
8.
9.
10.
Referenced to DTMF tone of lower amplitude.
Bandwidth limited: 0 to 3.4kHz Gaussian Noise.
Timing for an external input to the XTAL/CLOCK pin.
Over the range VDD = 3.3V to 5.5V at Tamb = 25°C.
 2001 Consumer Microcircuits Limited
24
D/605/6
Digital Line to POTS Interface
CMX605
Notes
Min.
Typ.
Max.
Unit
100
100
0.0
1.0
500
500
200
200
75
25
75
0
-
1.0
-
ns
ns
ns
µs
µs
ns
ns
ns
ns
ns
ns
ns
ns
‘C-BUS’ Timings (See Figure 8)
tCSE
tCSH
tLOZ
tHIZ
tCSOFF
tNXT
tCK
tCH
tCL
tCDS
tCDH
tRDS
tRDH
CSN-Enable to Clock-High time
Last Clock-High to CSN-High time
Clock-Low to Reply Output enable time
CSN-High to Reply Output 3-state time
CSN-High Time between transactions
Inter-Byte Time
Clock-Cycle time
Serial Clock-High time
Serial Clock-Low time
Command Data Set-Up time
Command Data Hold time
Reply Data Set-Up time
Reply Data Hold time
Note: These timings are for the latest version of the ‘C-BUS’ as embodied in the CMX605, and allow
faster transfers than the original ‘C-BUS’ timings given in CML Publication D/800/Sys/3 July 1994.
Notes
Min.
Typ.
Max.
Unit
-
-
106
833
208
625
-
µs
µs
µs
µs
Typical UART Timings (See Figures 3a and 3b)
TFSK
TDLY
TDRDY
TUFL
(delay through the modulator)
(1 bit period)
(¼ bit-period)
(3/4 bit-period)
Figure 8 ‘C-BUS’ Timing
 2001 Consumer Microcircuits Limited
25
D/605/6
Digital Line to POTS Interface
1.7.2
CMX605
Packaging
Figure 9 16-pin SOIC (D4) Mechanical Outline: Order as part no. CMX605D4
Figure 10 16-pin DIL (P3) Mechanical Outline: Order as part no. CMX605P3
Handling precautions: This product includes input protection, however, precautions should be taken to prevent device damage from
electro-static discharge. CML does not assume any responsibility for the use of any circuitry described. No IPR or circuit patent licences
are implied. CML reserves the right at any time without notice to change the said circuitry and this product specification. CML has a
policy of testing every product shipped using calibrated test equipment to ensure compliance with this product specification. Specific
testing of all circuit parameters is not necessarily performed.
Oval Park - LANGFORD
MALDON - ESSEX
CM9 6WG - ENGLAND
Telephone: +44 (0)1621 875500
Telefax:
+44 (0)1621 875600
e-mail:
[email protected]
http://www.cmlmicro.co.uk
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
CML Product Data
In the process of creating a more global image, the three standard product semiconductor
companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc
(USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst
maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA)
Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML Microcircuits.
These companies are all 100% owned operating companies of the CML Microsystems Plc
Group and these changes are purely changes of name and do not change any underlying legal
entities and hence will have no effect on any agreements or contacts currently in force.
CML Microcircuits Product Prefix Codes
Until the latter part of 1996, the differentiator between products manufactured and sold from
MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX
respectively. These products use the same silicon etc. and today still carry the same prefixes.
In the latter part of 1996, both companies adopted the common prefix: CMX.
This notification is relevant product information to which it is attached.
Company contact information is as below:
CML Microcircuits
(UK)Ltd
CML Microcircuits
(USA) Inc.
CML Microcircuits
(Singapore)PteLtd
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
Oval Park, Langford, Maldon,
Essex, CM9 6WG, England
Tel: +44 (0)1621 875500
Fax: +44 (0)1621 875600
[email protected]
www.cmlmicro.com
4800 Bethania Station Road,
Winston-Salem, NC 27105, USA
Tel: +1 336 744 5050,
0800 638 5577
Fax: +1 336 744 5054
[email protected]
www.cmlmicro.com
No 2 Kallang Pudding Road, 09-05/
06 Mactech Industrial Building,
Singapore 349307
Tel: +65 7450426
Fax: +65 7452917
[email protected]
www.cmlmicro.com
D/CML (D)/1 February 2002