CMLMICRO DE8681

DE8681
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
V.22bis User Manual
for a "socket modem"
UM8681/3 January 2004
1.0
Provisional Issue
Features
• CMX868-based socket modem Reference Design
• PC Controlled via Terminal Emulator
• Fully Isolated 2-Wire Line Interface
• FCC68 or CTR21 DAA
• Opto Isolated Ring Detect Circuitry and
OptoMOS Hook Relay
• Single 3V or 5V dc power supply
operation
• ‘AT’ Command Compatible Firmware
• Break-off PCB sections
• On-board FLASH PIC Microcontroller
• Supplied with PCB layout data
1.1
Brief Description
The DE8681 Demonstration Board is a reference design for the CMX868 V.22 bis modem IC. On the
main "socket modem" section it also contains the line interface components and a Flash PIC µC.
Attached to the main section are two break-off sections which contain a 9-pin D type socket for PC serial
communications, a Flash PIC programming connector, an RJ11 line connector and various LEDs for
indicating signal activity. AT Commands are used to control the demonstration board via a standard
terminal emulator program running on a host PC.
Interfacing to the Demonstration Board can be via socket pins on the socket modem section, or via the
connectors provided on the break-off sections. The board can be operated at 3V or 5V dc, which must be
provided by an external, regulated power supply.
The PCB has been laid out for both CTR21 and FCC68 compliant DAA designs. However the
components fitted are for the simplified FCC68 design. Instructions are given for users who wish to fit
the CTR21 components. Hardware has been provided on the socket modem section for CLI Type 1, but
a PIC firmware upgrade will be required to enable this function, which may be available at a later date.
With this is mind, the socket modem has been provided with a Flash PIC Microcontroller that can be
serially programmed in circuit via the RS232 connection.
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CMX868 Reference Design and Demonstration Board
DE8681
CONTENTS
Section
Page
1.0
Features ............................................................................................... 1
1.0
Features ............................................................................................... 1
1.1
Brief Description.................................................................................. 1
1.2
Preliminary Information ...................................................................... 4
1.2.1 Equipment ............................................................................... 4
1.2.2 Handling Precautions ............................................................. 4
1.2.3 Approvals ................................................................................ 4
1.3
Quick Start ........................................................................................... 5
1.3.1 Setting-Up................................................................................ 5
1.3.2 Operation................................................................................. 5
1.4
Signal Lists .......................................................................................... 7
1.5
Circuit Schematics and Board Layout.............................................. 10
1.6
Detailed Description .......................................................................... 14
1.6.1 Hardware Description ........................................................... 14
1.6.2 Firmware Description............................................................ 15
1.6.4 Software Description ............................................................ 26
1.6.5 Additional Information.......................................................... 28
1.6.6 Example DE8681 Modem Tests ............................................ 30
1.6.7 Example DE8681 Device Evaluation Tests .......................... 31
1.6.8 Trouble Shooting .................................................................. 33
1.7
Performance Specification................................................................ 34
1.7.1 Electrical Performance.......................................................... 34
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CMX868 Reference Design and Demonstration Board
DE8681
Modem
or
Telephone Line
Simulator
J3
J61
DE8681
Power
Supply
J26/J41
J4
RS232 Cable
IBM-PC
Figure 1 Block Diagram
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1.2
Preliminary Information
1.2.1
Equipment
DE8681
The following equipment is needed to use this demonstration board:
1.2.1.1 3Vdc or 5Vdc Regulated Power Supply
1.2.1.2 A PC equipped with a serial port running a terminal emulation program such as Microsofts’
Hyperterminal.
1.2.1.3 For PIC re-programming with the software supplied (PICPROGF.EXE), an IBM compatible PC,
66MHz ‘486 or better, running Microsoft WindowsTM 95,98 or DOS. The software runs most
efficiently under DOS and cannot be used with Windows NT.
1.2.2
Handling Precautions
1.2.2.1 Static Protection
This product uses low power CMOS circuits, which can be damaged by electrostatic discharge.
Partially damaged circuits can function erroneously, leading to misleading results. Observe ESD
precautions at all times when handling this product.
1.2.2.2 Contents - Unpacking
Please ensure that you have received all of the items on the separate information sheet
(EK8681) and notify CML within 7 working days if the delivery is incomplete.
1.2.3
Approvals
This product is designed to meet CTR21/FCC68 telecom approval requirements. Users
are advised to observe local statutory requirements which may apply to this product
before direct or indirect connection to any public telecommunication system.
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CMX868 Reference Design and Demonstration Board
1.3
DE8681
Quick Start
This section provides instructions for users who wish to experiment immediately with the
demonstration board. A fuller description of the board and its use appears later in this document.
1.3.1
Setting-Up
THE DE8681 COMES PRE-CONFIGURED AS A FCC68 MODEM, USING THE CMX868
TSSOP DEVICE AND A PRE-PROGRAMMED FLASH PIC µC, FOR OPERATION AT 5.0
VOLTS.
See section 1.6 for the alternative component values required for 3.0V or CTR21
operation.
An RJ11 (US style) phone jack, J3, for 2-wire line connection is provided on one of the break-off
board sections. Power is connected via socket pins 61(VDD) and 41(GND). See pinout, figure 2.
Attach the 9-way RS232 cable between connector J4 and the serial port of the PC. Connect an
external modem/line simulator to the evaluation kit using a suitable RJ11 telephone cable (not
supplied).
The DE8681 is supplied with the break-off sections of the board intact. If a socket modem using
the industry standard footprint is required, detach these break-off sections from the
Demonstration Board PCB by using a suitable tool to scribe along the perforations that join the
break-off sections to the main PCB. Scribe on both top and bottom sides of the board and
ensure that the scribed line completely cuts any copper tracks entering or leaving the break-off
sections from the main PCB. When this is done, gently break-off the first section on which
connector J4 (9-pin D Type socket) is mounted, then break-off the second section on which the
RJ11 socket is mounted. All connections to the remaining socket modem must now be made
through the PCB connector pins.
1.3.2
Operation
The DE8681 demonstration board allows the user to perform calling, answering and simple data
transfer with a suitable simulator or external third party modem (not supplied).
The board is controlled by the AT command set described in Section 1.6.3, by running a terminal
emulator program on the host PC. A suitable emulator is the ‘HyperTerminal’ program, which
operates under Windows 95/NT systems. The DE8681 AT command set consists of Basic,
Extended and CML Specific commands.
The board has two modes of operation:
AT Command Mode
In this mode the command processor firmware is constantly checking to see if the user has typed
a valid AT command. When a valid command is received the firmware will execute that
command. While the firmware is operating in this mode, the user can instruct it to manually
answer a call, originate a call, go on/off hook, read/write to S-registers, issue CML specific AT
commands, and perform any number of other AT command functions.
The board always starts in AT Command mode after power is applied and board initialisation is
complete.
The CML specific AT commands allow the user to directly control the CMX868 device for
evaluation purposes. Note, customer modified CMX868 device registers will be overwritten when
Dial and Answer AT commands are executed.
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DE8681
The Dial and Answer commands will execute the relevant DTMF transmit, call progress tone
detection and negotiation (handshaking) firmware routines before a connection to a remote
modem/simulator can be established. Negotiation may be aborted by pushing any key.
Note, if the S0 register is modified to a non-zero value during this operating mode, the CMX868
status register will be polled every 20ms to check for ring detect status. If valid ringing is
detected the DE8681 will automatically answer a call after n ring cycles, where n is equivalent to
the contents of the S0 register.
Data Transfer Mode
After gaining a connection (i.e. successful negotiation) with a remote modem the board will be
operating in data transfer mode. In this mode the board will transmit all the data it receives from
the RS232 computer terminal to the remote modem via the 2-wire line. Likewise any data
received from the remote modem via the 2-wire line will be sent to RS232 computer terminal.
Whilst operating in this mode the data stream from the RS232 computer terminal is monitored for
the escape code sequence (+++). If this sequence is encountered during data transfer the
firmware will revert to on-line AT command mode. Whilst in on-line, AT command mode, the
board to remote modem connection may be aborted by typing ATH0 (instructs modem to go onhook). Alternatively the user can enter relevant AT commands or return to data transfer mode by
using the ATO command.
The modem line speed is much lower than the speed of the RS232 interface (RS232 is running at
19200bps) and the DE8681 firmware only provides a small amount of data buffering. Therefore
to prevent the data buffer from overflowing the data flow between the µC and RS232 is controlled
by the RTS/CTS (Request/Clear to Send) hardware handshake lines.
The CMX868 settings used during negotiation and data transfer will be based on the contents of
the S-registers when the call was originated or answered. The S-registers are described in
Section 1.6.3. Certain S-register settings (relevant to the CMX868 configuration), modified
during on-line AT command mode, will only take effect when a new call is originated or
answered. For example, new CMX868 Tx gain settings (S25 register) modified in on-line AT
command mode will be ignored until the next call.
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1.4
DE8681
Signal Lists
CONNECTOR PINOUT
Connector
Ref.
Signal
Name
Signal
Type
Description
J1
TIP
Bi
Socket pin - Tip
J2
RING
Bi
Socket pin – Ring
3
RING
Bi
RJ11 connector – Ring
4
TIP
Bi
RJ11 connector – Tip
1
DCD
Output
9-pin D Type connector – PC DCD
2
TXD
Output
9-pin D Type connector – PC TXD
3
RXD
Input
9-pin D Type connector – PC RXD
4
DTR
Input
9-pin D Type connector – PC DTR
5
VSS
Power
9-pin D Type connector – PC GND
6
DSR
Output
9-pin D Type connector - PC DSR
7
RTS
Input
9-pin D Type connector – PC RTS
8
CTS
Output
9-pin D Type connector - PC CTS
9
RI
Output
9-pin D Type connector – PC RI
1
/RESET
Input
1 x 5 header – PIC reset
2
/CTSTTL
Input
1 x 5 header – PIC programming data
3
/RTSTTL
Input
1 x 5 header – PIC programming clock
4
VPP
Power
1 x 5 header – PIC programming voltage
5
Vss
Power
1 x 5 header Vss connection
J24
/RESET
Input
Socket pin – PIC reset
J26
VSS
Power
VSS connection
J29
DCDIND
Output
Socket pin – DCD LED indication
J30
RXDIND
Output
Socket pin – RXD LED indication
J31
DTRIND
Output
Socket pin – DTR LED indication
J32
TXDIND
Output
Socket pin – TXD LED indication
J33
/RTSTTL
Input
Socket pin – PIC RTS
J34
/RXDTTL
Output
Socket pin – PIC TXD
J35
/TXDTTL
Input
Socket pin – PIC RXD
J36
/RITTL
Output
Socket pin – PIC RI
J37
/DSRTTL
Output
Socket pin – PIC DSR
J38
/CTSTTL
Output
Socket pin – PIC CTS
J3
J4
J5
Connector
Pin No.
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CMX868 Reference Design and Demonstration Board
DE8681
CONNECTOR PINOUT
Connector
Ref.
Connector
Pin No.
Signal
Name
Signal
Type
Description
J39
/DCDTTL
Output
Socket pin – PIC DCD
J40
/DTRTTL
Input
Socket pin – PIC DTR
J41
Vss
Power
Vss connection
J61
VDD
Power
+ve power from external power supply
J63
AVss
Power
Analogue Vss connection – Not used
LEDs
LED
Ref.
Description
D7
Illuminated when the line is in an off-hook state
D8
Illuminated when a carrier is detected at the remote
modem end of the line
D9
Iluminated when the Socket Modem (DCE) is transmitting
data to a host (DTE)
D10
Illuminated when the Socket Modem is receiving data
from a host
D11
Illuminated when Data Terminal Ready is asserted by the
host system.
JUMPERS
Jumper
Ref.
Positions
Default
Position
Description
JP1
1-2
S/C
Receiver enable (U8)
Notes: Bi
S/C
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Bidirectional
Short Circuit
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UM8681/3
CMX868 Reference Design and Demonstration Board
DE8681
C11
C12
TIP J1
RING J2
E1
J61 VDD
T1
R13
D6
C10
C8
D1
R8
R6
R5
R9
R1
X1
C24
R7
C2
C1
C6
C23
DCDIND J29
RXDIND J30
DTRIND J31
TXDIND J32
C4
U1
C7
GND J26
C5
R4
U2 C3
/RESET J24
C13
J41 GND
J39
J38
J37
J36
J35
J34
J33
/DCDTTL
/CTSTTL
/DSRTTL
/RITTL
/TXDTTL
/RXDTTL
/RTSTTL
Figure 2, socket section pinout.
Users with a revision B board, PCB024B, must note that the polarity for C11 shown on the
silk screen is incorrect. Figures 2 and 5 of this document show corrected polarity.
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UM8681/3
C4
VDD
Break-off section
22pF
C2
22pF
D7
Hook state indication
620R
R16
11M0592Hz
X1
100nF
C13
IRQN
VDD
R2
100k
21
REPDATA
U1
CMX868E2
VSS
RDATA
R3
VDD
20k
470k
R1
VDD
VDD
C3
100nF
330nF
C5
6 RT
7 VDD
C1
100nF
100k
100pF
R4
C7
330nF
C6
VDD
5k6
56k
R5
R6
R7
180k
5 VDD
C23
100nF
GND 3
EN
4
NO 2
MAX4501CUK-T
U2
C24
220pF
1 COM
R9
120k
OFFHOOK
2u2F
390R
C8
100nF
C10
R8
D1
1
3
2
4v3
SEC(Modem)
3
4
T1
2
1
U4
3
AC
PRI(Line)
D5
1
D4
2
100nF
C9
33v (600W)
1
CBRHD-02
2, 4
U5
FZT605
AC
3
MIDCOM82107
10uF (50V)
C11
2
1
BC846ALT1
11R5
R11
+
-
SCLK
TXAN
13
VBIAS
RXA
U3
33k
R10
3
2
D2
D3
1
3
4
1
2
NECPS2701-1
18v
R13
10k (0.5W)
C12
330nF (250v)
U6
R12
620R
VDD
1
CDATA
VSS 17
8 VSS
9 RXAFB
VDD 24
IRQN 23
22
1 XTALN
SERCLK 20
COMDATA 19
CSN 18
2 XTAL/CLK
3
RLYDRV
4
VSS
5 RD
VDD 16
TXA 15
14
RXAN
10
VSS
11
10
12
2
6
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VDD
2
1
E1
F1
1.25A
1
3
5
RING
RJ11SKT
J3
2
4
6
Break-off section
ISOLATION BARRIER
TIP
ISOLATION BARRIER
OFFHOOK
1.5
4
CSN
CMX868 Reference Design and Demonstration Board
DE8681
Circuit Schematics and Board Layout
Figure 3a Modem Section with CTR21 Components
UM8681/3
VDD
Break-off section
22pF
C2
22pF
C4
Hook state indication
620R
R16
D7
11M0592Hz
X1
C13
100nF
VDD
R2
100k
U1
CMX868E2
VDD 24
VDD
20k
R3
XTALN
1
IRQN
IRQN 23
XTAL/CLK
2
RDATA
470k
R1
VDD
VDD
100nF
C3
18
330nF
C5
100nF
C1
TXAN
100k
100pF
R4
C7
330nF
C6
VDD
5k6
62k
R5
R6
R7
180k
5
1
R9
120k
VDD
COM
NO
4
2
GND 3
EN
MAX4501CUK-T
U2
C24
47pF
C23
100nF
OFFHOOK
0R
R8
390R
C8
33nF
C10
D1
1
3
2
4v3
SEC(Modem)
3
4
T1
2
1
AC
nf
U4
3
2
PRI(Line)
MIDCOM82111
1
nf
C11
nf
R11
+
-
SCLK
22
REPDATA
RLYDRV
3
14
VBIAS 13
RXA
1
1
2
100nF
0R
D4
nf
2, 4
C9
U5
nf
D5
AC
3
U3
nf
R10
3
2
D2
D3
1
3
4
1
2
NECPS2701-1
18v
R13
10k (0.5W)
C12
330nF (250v)
U6
R12
620R
VDD
1
6
CDATA
VSS
VSS
4
19
COMDATA
21
SERCLK 20
RD
5
16
CSN
VDD
7
RT
6
15
VSS 17
VSS
8
TXA
VDD
RXAFB
9
RXAN
10
VSS
11
11
12
2
5
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CSN
VDD
2
1
E1
1.25A
F1
1
3
5
RING
RJ11SKT
J3
2
4
6
Break-off section
ISOLATION BARRIER
TIP
ISOLATION BARRIER
OFFHOOK
CMX868 Reference Design and Demonstration Board
DE8681
Figure 3b Modem Section with FCC68 DAA Components (default)
UM8681/3
J1
TIP
J2
J24
RING /RESET
D11
D10
D9
D8
R17
J26
J29
J30
RXDIND
DTRIND
TXDIND
RXDIND
DCDIND
DCDIND
680R
R20
680R
R19
680R
680R
R18
X2
SCLK
15pF
CSN
4MHz
RS2
1M
J31
J32
J33
DTRIND TXDIND /RTSTTL
C15
C14
15pF
RS1
1M
1
8
7
6
5
1
2
3
4
Break-off section
SW1
8
7
6
5
2
J35
/TXDTTL
RS3
1M
RC5/SDO
RC6/TX/CK
RC7/RX/DT
J36
/RITTL
8
7
6
5
/CTSTTL
J37
/DSRTTL
RS4
1M
15
/RITTL
/DTRTTL
J38
/CTSTTL
J39
/DCDTTL
J40
/DTRTTL
J41
J61
VDD
D6
6.2v (1W)
J63
15
16
/RXDTTL
19
20
21
22
23
24
25
26
27
28
16
/TXDTTL
C18
100nF
MBAUD
R1OUTB
T5IN
R3OUT
T4IN
R2OUT
R1OUT
T3IN
T2IN
T1IN
C1-
VCC
V+
C1+
470nF
C19
100nF
C21
17
CDATA
/DSRTTL
/DCDTTL
C22
100uF (16V)
17
RDATA
/RTSTTL
R14
10k
47uH
L1
18
100nF
IRQN VDD C20
RS5
1M
VDD
VDD
Break-off section
18
VDD 20
VSS 19
RB1 22
21
RB0/INT
RC4/SDI/SDA
PIC16LF876SO
RC3/SCK/SCL
RC2/CCP1
RC1/T1OSC/CCP2
RC0/T1OSO/T1CKI
OSC2/CLKOUT
VDD
14
13
12
11
10
9 OSC1/CLKIN
7 RA5//SS/AN4
8 VSS
RB3 24
RB2 23
RB5 26
RB4 25
5 RA3/AN3/Vref
6 RA4/T0CKI
3 RA1/AN1
4 RA2/AN2
U7
VDD
RB7 28
RB6 27
/RXDTTL
J34
R21
100k
1 /MCLR/Vpp
2 RA0/AN0
VDD
D12
VPP
4
3
2
1
5
6
7
8
1
2
3
4
R22
270R
4
3
2
1
12
5
6
7
8
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2
3
4
/RESET
MAX3237CAI
U8
VPP
/RTSTTL
/CTSTTL
/RESET
1
/SHDN
/EN
14
13
R3IN 11
T5OUT 12
R2IN 9
T4OUT 10
T3OUT 7
R1IN 8
V- 4
T1OUT 5
T2OUT 6
GND 2
C2- 3
C2+
VDD
RI
TXD
RTS
DTR
CTS
VDD
R23
10k
JP1
2
DB9F_CML
RXD
J4
1
2
3
4
5
6
7
8
9
DSR
DCD
1
C16 470nF
470nF
C17
J5:E
J5:D
J5:C
J5:B
J5:A
CMX868 Reference Design and Demonstration Board
DE8681
Figure 4 Control Section (common)
UM8681/3
CMX868 Reference Design and Demonstration Board
C18
C19
D6
T1
X1
C10
R6
U2
C8
U8
C22
R14
C3
C17 C16
R8
D1
R5
R9
R4
C6
C23
R7
R13
C24
1
SW1
J5
Board Mod
1 2 3 4
C2
C1
E1
J3
C4
U1
C7
C12
C5
C13
R1
+
C11
DE8681
R16
R17 R18 R20 R19
J4
R23
R22
JP1
D7
D8 D9 D11 D10
HOOK DCD RXD DTR TXD
F1
Figure 5 DE8681 top silk screen
R12
D12
R21
RS1
RS2
X2
R11
U4
RS5
D5
C14
L1
D4
U6
+
PIC16LF876SO
C21
C20
R2
D3
R3
RS4
R10
C9
U3
U5
C15
U7
RS3
D2
Figure 6 DE8681 bottom silk screen
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CMX868 Reference Design and Demonstration Board
1.6
Detailed Description
1.6.1
Hardware Description
DE8681
1.6.1.1 Operating Voltage
The DE8681 can be operated at a VDD of 3 or 5Vdc (default), supplied by an external regulated
power supply. Tables of component values for CTR21 and FCC68 DAAs are shown below:
CTR21 DAA
VDD
3.0 V
5.0 V
R6
91K (93.5K)
56K (57.6K)
R7
160K
180K
C24
180pF
220pF
FCC68 DAA
VDD
R6
R7
C24
3.0 V
100K (107K) 160K
39pF
5.0 V
62K (64.9K)
180K
47pF
(The values shown in brackets are optimal values)
R12
220R
620R
D1
3.0V
4.3V
R12
220R
620R
D1
3.0V
4.3V
1.6.1.2 Clock/Oscillator
The CMX868 is clocked at a frequency of 11.0592MHz, which is provided by crystal X1. The PIC
µC is clocked with a 4MHz crystal, X2. PIC microcontrollers programmed by CML are only
configured for use with the on-board 4MHz crystal.
1.6.1.3 On-hook Caller ID
This function provides a high impedance, on-hook AC path for the routing of Caller ID signals to
the CMX868. Components C9, R5 and U2 provide this transmission path. C9 bypasses the
optoMOS relay hook switch, allowing AC signals to pass through T1 when the Socket Modem is
in an on-hook state. To compensate for losses incurred in the on-hook state, U2 and R5 increase
the receive gain of the CMX868.
1.6.1.4 Simplified FCC68 Compliant DAA, as Shipped
The values of R4, R6, R7, R8, R9, C8 and C24 are optimal values with respect to the Midcom
82111 transformer. Parts C10 and D4 are not required for this simplified design but are replaced
with 0Ω links.
1.6.1.5 CTR21 Compliant DAA
Components R10, R11, C11, D4, D5, U4 may be fitted to provide a 60mA current limit required
by CTR21. Users with a revision B board, PCB024B, must note that the polarity for C11
shown on the silk screen is incorrect. Figures 2 and 5 of this document show corrected
polarity.
An alternative transformer, the Midcom 82107, must be fitted. Parts C10, C24, and R6 also have
different values, to match the characteristics of the 82107 transformer and the CTR21 reference
impedance. To be compliant with the CTR21 DTMF twist requirement, users must set S-register
S28 bits 2-0 to 4. Please note that this will only be effective on DE8681 boards with a board mod
state of 2 or higher, boards with a board mod state of 1 cannot meet the CTR21 DTMF twist
requirement.
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DE8681
1.6.1.6 Line Protection
Line protection is provided by the Sidactor component E1. Sidactor is the trade name for a type
of Transient Voltage Suppressor (TVS) manufactured by Teccor Electronics.
1.6.1.7 Ring Detection
The ring detect threshold is approximately 20VRMS.
1.6.2
Firmware Description
The PIC16LF876-04/SP µC fitted on the DE8681 demonstration board has been programmed by
CML before shipment with the latest version of firmware. Please read the separate information
sheet (EK8681) and check the CML web site for firmware status. The latest source code and
programming file (EF8681xx.HEX, where xx represents the version number) can be downloaded
from the CML web site.
The serial communications firmware supplied in the PIC µC assumes the following configuration:
8 data bits, no parity, 1 stop bit and 19,200 baud with hardware flow control.
The firmware routine run at start-up and reset performs the following important tasks:
Peripheral Interrupt Initialisation
µC ports and I/O direction initialisation
Serial Communication Interface (SCI) initialisation
Serial Peripheral Interface (SPI) initialisation
Loads factory profile 0
Resets CMX868 device.
The message EF8681 Vx.x, will be displayed in the terminal emulator window when these tasks
have been completed.
Note, the CMX868 device is always reset and powered up at the beginning of the negotiation.
The firmware only supports DTMF dialling.
AT command echoing is an option available in the firmware and involves echoing the received
characters sent by the PC. The firmware also provides the option of sending result codes to the
PC. These responses can be in either an alpha or numeric form.
The AT command set for the DE8681 is tabulated below. These commands can be entered on a
PC running Windows terminal emulator software, such as the ‘HyperTerminal’ program supplied
with Windows 95/NT systems.
The ‘HyperTerminal’ Send Text File facility is useful for data transfer i.e. when the DE8681 has
established a connection with a remote modem. This terminal emulator facility can also be used
for sending AT command scripts to the DE8681. These scripts should consist of a single line
multiple AT command, for example.
[email protected][email protected][email protected]=4567<CR>
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DE8681
Basic DE8681 AT Commands
Command
Description
A
Answer Command
The modem will go off-hook and attempt to establish a connection with a remote
modem.
Syntax: ATA<CR>
A/
Re-Execute Previous Command Line
Re-executes the last issued command line. This command does not require the AT
prefix or a carriage return.
Syntax: A/
Bn
Select Communications Standard
Selects the communications standard specified by the parameter n.
Syntax: ATBn<CR>
Modifier Usage
n=0 Selects ITU-T V.22bis at 2400bps QAM (default).
n=1 Selects ITU-T V.22 at 1200bps DPSK.
n=2 Selects ITU-T V.23 with Tx 75bps and Rx 1200bps FSK.
n=3 Selects ITU-T V.23 with Tx 1200bps and Rx 75bps FSK.
n=4 Selects ITU-T V.22 at 600bps DPSK.
n=5 Selects ITU-T V.21 at 300bps FSK.
n=6 Selects Bell 212A at 1200bps DPSK.
n=7 Selects Bell 202 with Tx 150bps and Rx 1200bps FSK.
n=8 Selects Bell 202 with Tx 1200bps and Rx 150bps FSK.
n=9 Selects Bell 103 at 300bps FSK.
Dn
Dial Command
This command directs the modem to go off-hook, dials according to the string
entered and attempts to establish a connection with a remote modem. The n
represents an ASCII string composed of dial digits and dial modifiers and must not
exceed the 15 character buffer limit. The DTMF tone dialling digits include 0
through 9, A, B, C, D, and the symbols # and *.
For example: ATD9,01621875500<CR>
Modifier Usage
n=L Re-dial last number.
n=,
Delay dial sequence (pause setting contained in S-Register S8).
En
Echo Command Characters
Syntax: ATEn<CR>
Modifier Usage
n=0 Disables the echoing of commands to the screen.
n=1 Enables echoing of commands to the screen (default).
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Command
Hn
DE8681
Description
Switch Hook Control
Syntax: ATHn<CR>
Modifier Usage
n=0 Instructs the modem to go on-hook (disconnect).
n=1 Instructs the modem to go off-hook.
In
Identification
Requests the modem to return its product identification information.
Syntax: ATIn<CR>
Modifier Usage
n=0 Displays the firmware name and version number.
n=1 Displays Product Name.
n=2 Displays CML UK sales information.
n=3 Displays South East Asia sales information.
n=4 Displays NAFTA sales information.
Nn
Modulation Fallback Option
Syntax: ATNn<CR>
Modifier Usage
n=0 When originating or answering, modem negotiates only at the specified
communications standard (default).
n=1 When originating or answering, falls back from V.22bis to V.22 as required.
O
Return to Data Transfer Mode
Used during on-line AT command mode, this command allows the user to return to
data transfer mode. Note, this command does not initiate any retrain sequence.
Syntax: ATO<CR>
Qn
Enable/Disable Modem Responses
Syntax: ATQn<CR>
Modifier Usage
n=0 Enables result codes to be issued to the screen (default).
n=1 Disables result codes to be issued to the screen.
Sn?
S-Register Read
Command for displaying the contents of an S-Register (See S-Register Table).
Syntax: ATSn?<CR>
where n is the S-Register to be interrogated (decimal).
Value returned is either in decimal (default) or hex format depending on the setting
of Bit 4 in the S14 register.
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Command
Sn=x
DE8681
Description
S-Register Write
Command for writing to an S-Register (See S-Register Table).
Syntax: ATSn=x<CR>
where n is the S-Register (decimal) and x is the value to be written (decimal, 0255).
Vn
Result Code Format
Syntax: ATVn<CR>
Modifier Usage
n=0 Instructs the modem to display result codes as numbers.
n=1 Instructs the modem to display result codes as words (default).
Xn
Calling Characteristics
Determines which set of responses and calling characteristics are used.
Syntax: ATXn<CR>
Modifier Usage
n=0 The modem will ignore dial tones and busy tones. Dial tone wait time is zero,
and blind dialling is enabled. The modem returns a CONNECT result code when a
connection is established.
n=1 The modem will ignore dial tones and busy tones. Dial tone wait time is zero,
and blind dialling is enabled. The modem returns a CONNECT xxxx result code
when a connection is established, where xxxx is the Tx/Rx line speed (default).
n=2 The modem will ignore busy tones, but waits for a dial tone before dialling. If a
dial tone is not detected within 5 seconds, a NO DIAL TONE result code is
returned. The modem returns a CONNECT xxxx result code when a connection is
established, where xxxx is the Tx/Rx line speed.
n=3 The modem will ignore dial tones. If a busy tone is detected, a BUSY result
code is returned. Blind dialling is enabled. The modem returns a CONNECT xxxx
result code when a connection is established, where xxxx is the Tx/Rx line speed.
n=4 If a dial tone is not detected within 5 seconds, a NO DIAL TONE result code is
returned. If a busy tone is detected, a BUSY result code is returned. The modem
returns a CONNECT xxxx result code when a connection is established, where
xxxx is the Tx/Rx line speed.
Zn
Modem Reset
Instructs the modem to reset the evaluation device and then reload the factory SRegister settings (See S-Register Table).
Syntax: ATZn<CR>
Modifier Usage
n=0 Reset CMX868 device and restore factory profile 0.
n=1 Reset CMX868 device and restore factory profile 1.
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DE8681
Extended DE8681 AT Commands
Command
Description
&Fn
Recall Factory Defaults
Instructs the modem to reload the factory S-Register settings (See S-Register
Table).
Syntax: AT&Fn<CR>
Modifier Usage
n=0 Recalls factory profile 0.
n=1 Recalls factory profile 1.
&Gn
Guard Tone Select
Selects the Guard tone to be transmitted with highband QAM or DPSK.
Syntax: AT&Gn<CR>
Modifier Usage
n=0 Disable guard tone (default).
n=1 Enable 550Hz guard tone.
n=2 Enable 1800Hz guard tone.
CML Specific DE8681 AT Commands
Command
@Fn
Description
Test Functions
Syntax: [email protected]<CR>
Modifier Usage
n=0 Reserved.
n=1 Reserved.
n=2 Delay 100ms.
n=3 Delay 1s.
n=4 Initiate BERT as Rx End. (Disabled for EF8681 Version 1.0 Firmware)
n=5 Initiate BERT as Rx End. (Disabled for EF8681 Version 1.0 Firmware)
n=6 CMX868 Status Register Monitor Function 1. Continuously reads and displays
the contents of the Status register. The update rate is based on the S19 register
setting. The function may be aborted by pushing any key.
n=7 CMX868 Status Register Monitor Function 2. Reads and displays the contents
of the Status register when an interrupt occurs. Error message returned after 30
seconds if IRQN does not go low. User must enable IRQN output and set the
appropriate IRQ Mask bit before executing this test command.
n=8 Reserved.
n=9 Reserved.
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DE8681
Command
Description
@D
DTMF Transmit (Only available on boards with a board mod state of 2 or
higher)
CMX868 will constantly transmit a selected DTMF tone dialling digit.
Syntax: [email protected]<CR>nn..nX
Modifier Usage
n = 0-9, A, B, C, D, * or # The DTMF dialling digit to be transmitted.
X = any other key Terminates the function.
@RR
CMX868 Device Reset
Sends the General Reset Command to the CMX868 device.
Syntax: [email protected]<CR>
@Rn?
CMX868 Register Read
Command for displaying the contents of a CMX868 device register
Syntax: [email protected]?<CR>
where n is a valid CMX868 register address (hexadecimal).
Value returned is either in decimal (default) or hex format depending on the setting
of Bit 4 in the S14 register.
@Rn=x
CMX868 Register Write
Command for writing to a CMX868 device register.
Syntax: [email protected]=x<CR>
where n is a valid CMX868 register address (hexadecimal) and x is the value to be
written (decimal). 8-bit register values should be between 0-255, whilst 16-bit
register values should be between 0-65535.
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DE8681
S-Registers
The following table gives a brief description of the available S-registers and their functions. Register
range, units and factory profiles are also listed.
S-Register
Reg
Range
Units
Description
Factory Profiles
‘0’
‘1’
(Default at
Power up)
0
5
S0
0-255
Rings
Automatic answer - Number of rings until
automatic answer. If the register is zero the
modem will not automatically answer.
S1
0-255
Rings
Count incoming rings - This register is read
only and contains the number of rings
detected by the modem.
0
0
S2
0-127
ASCII
Decimal
Escape character value - This register
defines an ASCII decimal value of the
escape character. The default setting is an
ASCII + and the escape sequence is +++. A
value over 127 disables the escape
sequence.
43
43
S3
0-127
ASCII
Decimal
Carriage return character - Contains the
ASCII decimal value of the character
recognised as the command line terminator.
This character will also be sent at the end of
result codes.
13
13
S4
0-127
ASCII
Decimal
Line feed character - Contains the ASCII
decimal value of the character recognised by
the modem as the line feed. The modem
sends the line feed character after a carriage
return only when word responses are sent.
10
10
S5
0-127
ASCII
Decimal
Backspace character - Contains the ASCII
decimal value of the character recognised as
a backspace.
8
8
S6
2-255
s
Wait time for blind dialling - Sets the
length of time to pause after the modem
goes off the hook before the modem dials
the first digit of the telephone number.
2
2
S7
1-255
s
Wait for carrier after dial - Sets the length
of time the modem waits for a carrier before
returning on-hook.
50
50
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DE8681
S-Register
Reg
Range
Units
Description
Factory Profiles
‘0’
‘1’
(Default at
Power up)
2
2
6
7
6
7
S8
0-255
s
S9
S10
1-255
1-255
100ms
100ms
S11
5-25
10ms
DTMF tone duration - Defines the duration
of DTMF tones for tone dialling. The length
of pause between each DTMF tone is the
same as this duration time.
10
20
S12
0-255
50ms
Escape code guard time - Specifies the
minimum time before entry of the escape
sequence. This value also dictates the
acceptable entry speed (inter-character time)
for each escape character.
20
20
S13
S14
0-255
0-255
Decimal
Decimal
0
138
0
128
S15
S16
S17
0-255
0-255
0-255
Decimal
Decimal
Decimal
Reserved
General options - provides the following
functions:
Bit 0 - Reserved
Bit 1 - Echo command character, 0 Disables
echoing (ATE0), 1 Enables echoing
(ATE1)
Bit 2 - Result code display, 0 Send
responses (ATQ0), 1 Do not send
responses (ATQ1)
Bit 3 - Word or number responses, 0 Send
number responses (ATV0), 1 Send word
responses (ATV1)
Bit 4 - Output format when reading CMX868
registers or S-registers, 0 Decimal, 1 Hex
Bit 5, 6 – Reserved
Bit 7 - Answer/originate operation, 0
Answer (ATA), 1 Originate (ATD)
Reserved
Reserved
Reserved
0
0
0
0
0
0
 2004 CML Microsystems Plc
Pause Time for Comma Dial Modifier Specifies the number of seconds to pause
for each comma (,) encountered in a dial
string.
Reserved
Lost carrier to hang up delay - Sets the
length of time that the modem waits before
hanging up after the loss of a carrier. This
allows the modem to distinguish between
disturbances that momentarily break the
connection and the remote modem hanging
up.
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DE8681
S-Register
Factory Profiles
‘0’
‘1’
Reg
Range
Units
Description
S18
0-255
s
General Purpose Timer - Used for various
firmware functions.
30
30
S19
0-255
10ms
2
2
S20
S21
0-255
0-255
Decimal
Decimal
General Purpose Timer – Used for various
firmware functions
Reserved
BERT functions disabled for EF8681
Version 1.0 firmware.
0
193
0
193
BERT options - Provides the following
functions:
Bit 0 - BERT End, 0 Rx Board ([email protected]), 1
Tx Board ([email protected])
Bit 1 - BERT Operating Band (ignored for
V23/Bell202 BERT operation), 0 Low, 1
High
Bit 2, 3, 4, 5 - Reserved
Bit 6,7 - BERT Scrambler/Descrambler, 11
Enabled (64 ones detect circuit enabled),
10 Enabled (64 ones detect circuit
disabled), 00 Disabled
S22
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0, 1, 2, 3, 4 - Reserved
Bit 5, 6, 7 - Calling Characteristics, 000
(ATX0), 100 (ATX1), 101 (ATX2), 110
(ATX3), 111 (ATX4)
0
0
S23
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0, 1, 2, 3, 4, 5 - Reserved
Bit 6, 7 - Guard Tones (DPSK/QAM high
band operation only), 00 None (AT&G0), 11
550Hz (AT&G1), 10 1800Hz (AT&G2)
0
0
S24
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0 - CMX868 Xtal Freq, 0 12.2880MHz, 1
11.0592MHz
Bit 1 - CMX868 Tx and Rx Fixed
Compromise Equalisers (used during
negotiation and data transfer), 0 Enable,
1 Disable
Bit 2 - CMX868 Auto Equaliser (DPSK
operating modes, always enabled during
V22bis QAM operation), 0 Disable, 1
Enable
Bit 3, 4, 5, 6, 7 – Reserved
1
3
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DE8681
S-Register
Factory Profiles
‘0’
‘1’
Reg
Range
Units
Description
S25
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0, 1, 2 - CMX868 Tx Gain (used during
negotiation, data transfer and BERT),
111 0dB, 110 -1.5dB, 101 -3.0dB, 100 4.5dB, 011 -6dB, 010 -7.5dB, 001 9.0dB, 000 -10.5dB
Bit 3, 4, 5 - CMX868 Tx Data/Stop bits
(used during data transfer), 111 8/2 bits,
110 8/1 bits, 101 7/2 bits, 100 7/1 bits,
011 6/2 bits, 010 6/1 bits, 001 5/2 bits,
000 5/1 bits
Bit 6, 7 - CMX868 Tx Start-stop mode (used
during data transfer), 00 Odd parity, 01
Even parity, 10 No parity
176
176
S26
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0, 1, 2 - CMX868 Rx Gain (used during
negotiation, data transfer and BERT),
111 0dB, 110 -1.5dB, 101 -3.0dB, 100 4.5dB, 011 -6dB, 010 -7.5dB, 001 9.0dB, 000 -10.5dB
Bit 3, 4, 5 - CMX868 Rx Data and Parity bits
(used during data transfer), 111 8 data +
parity, 110 8 data, 101 7 data + parity,
100 7 data, 011 6 data + parity, 010 6
data, 001 5 data + parity, 000 5 data
Bit 6, 7 - CMX868 Rx USART (used during
data transfer), 00 2.3% overspeed, 01
1% overspeed, 10 No overspeed
48
176
S27
0-255
Decimal
Bit Mapped register - Provides the
following functions:
Bit 0, 1, 2, 3 - Reserved.
Bit 4, 5, 6, 7 - Communication Standard,
0000 (ATB0), 0001 (ATB1), 0010
(ATB2), 0011 (ATB3), 0100 (ATB4),
0101 (ATB5), 0110 (ATB6), 0111
(ATB7), 1000 (ATB8), 1001 (ATB9)
0
0
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DE8681
S-Register
Reg
Range
Units
Description
S28
0-255
Decimal
Bit Mapped register – Provides the
following functions:
Bit 0, 1, 2 – CMX868 DTMF Twist level,
000 +2.0dB, 001 +1.0dB, 010 +1.5dB,
011 +2.5dB, 100 +3.0dB, 101 +3.5dB,
110 +4.0dB, 111 +4.5dB (do not use in
conjunction with the 0dB Tx level setting)
These DTMF twist settings are only effective
on boards with a board mod state of 2 or
higher.
Factory Profiles
‘0’
‘1’
0
0
0
0
Bit 3, 4, 5, 6, 7 - Reserved.
S29
0-255
Decimal
Reserved
Modem Result Codes
Numeric Response (Decimal)
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
Alpha Response
OK
CONNECT
RING
NO CARRIER
ERROR
NO DIAL TONE
BUSY
CONNECT 2400
CONNECT 1200
CONNECT 600
CONNECT 300
CONNECT 1200/75
CONNECT 75/1200
CONNECT 1200/150
CONNECT 150/1200
NYI
(Not Yet Implemented)
AT Command Summary
1) The maximum command length is 48 characters, excluding the AT prefix and carriage return.
2) A user defined escape sequence (usually +++) is required to revert the modem from on-line (data
transfer mode) to the command mode, to allow the user to issue AT commands to the PIC.
3) Every command except for A/ and the escape sequence must begin with the AT prefix and be entered
by pressing a carriage return.
4) When the default command echoing and word result codes are enabled the firmware will send a LF
character directly after a CR character to ensure the terminal emulator display is legible.
5) Commands which are not fully implemented will return the result code ‘NYI’ (Not Yet Implemented).
6) Do not send AT commands to the Demonstration board until the previous result code (if enabled) has
been received.
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1.6.4
DE8681
Software Description
1.6.4.1 In-Circuit Programming of PIC16LF876
TO ENTER PROGRAMMING MODE
a) Remove power from board.
b) Ensure that jumper JP1 is fitted.
c) Apply 13Vdc programming voltage between pins 4(VPP) and 5(GND) of connector J5.
d) Apply 5Vdc board supply voltage between socket pins 26 or 41 (GND) and 61(VDD).
e) Connect a PC to the DE8681 using a standard RS-232 cable.
f) Open a DOS window on the PC and run PICPROGF.EXE
g) Reset the DE8681 board by operating SW1.
USING THE SOFTWARE –
PICPROGF.EXE
This is supplied on CD-ROM as a self-documented executable file PICPROGF.EXE for a PC
running DOS (either directly or as a DOS window in Windows 3.11 or ‘95). It is not
recommended for use on Windows NT systems. Please note that this programming software
does not meet the Arizona Microchip Technology verification requirements for a “production
quality” programmer. Also, it does not support the programming of ID.
The user interface consists of two windows. The top window contains the operating instructions
and status information. The bottom window contains prompting and progress information plus
user input. When the top window first appears the user will be prompted to enter the number of
the serial communications port to which the DE8681 board is connected, and then, which device
is to be programmed. For the DE8681 board select option 2, PIC16LF876. Once the user has
entered this information, the following commands may be selected:
Press F
to load file
Press C
to configure device.
Press E
to block erase the device.
Press P
to program target device.
Press V
to verify target device.
Press R
to read target device.
Press A
to view contents of program data array.
Press Esc to return to DOS.
A new function from the above table can be selected whenever the >ok prompt appears in the
bottom window.
Notes:
a) Programming files must be in the Intel hex format (.HEX) in order to be usable by this
programming software.
b) The PIC µC supplied has a Configuration Word which is preset to 3D31H. This selects the
configuration shown in the following table:
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DE8681
PIC16LF876 Configuration Word – 3D31H
Oscillator
Watchdog Timer
Powerup Timer
Code Protect
Brown Out Detect
Low Voltage Programming
Data EE Protect
Flash Program Write
Background Debug
XT
Off
On
Off
Off
Disabled
Off
Disabled
Disabled
The programming software currently defaults to 3D31H. Consult Arizona Microchip Technology
for more information on the Configuration Word.
c) The “block erase” command (E) erases the program memory and writes all 1’s to the
EEPROM.
d) For each of the commands E, P, R and V the user will be prompted to manually reset the
target µC, by pressing the RESET switch (SW1) on the DE8681 board. This is because PIC
programming always starts from location 0000 and the program counter can only be
incremented.
e) Pressing A will display the program data in the bottom window, formatted in pages of 48
consecutive locations. Use the <PageUp> and <PageDown> keys to scroll through the data.
Pressing <Esc> will return the user to the >ok prompt.
f) Programming a PIC16LF876 using the PICPROGF software takes approximately 2 minutes.
TO LEAVE PROGRAMMING MODE
a) Remove power from board (including the programming voltage, VPP).
b) Leave jumper JP1 fitted.
c) Apply VDD (3 or 5Vdc) to the board.
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DE8681
1.6.4.2 Terminal Emulator
Users will need to run a suitable terminal emulator on their PC in order to communicate with the
PIC µC on the DE8681. ‘HyperTerminal’, which is supplied with the Windows 95/NT installations,
is suitable for this purpose.
HyperTerminal Setup
Emulation VT100
ASCII Character set
ASCII Receiving:
COM Port Settings:
Wrap lines that exceed terminal width.
Bits per second
Data bits
Parity
Stop bits
Flow Control
1.6.5
19,200
8
None
1
Hardware
Additional Information
1.6.5.1 AT Command Text Files
To allow evaluation tests to be quickly and easily repeated it may be useful to create text files
containing single line multiple AT commands. Commands can be transferred to the PIC µC via
the ‘HyperTerminal’ send text file facility. Note, multiple text files may be required to perform a
test if any command lines exceed 48 characters.
1.6.5.2 Sending Text Files using ‘HyperTerminal’
The following is a description of how to send text files to the DE8681 using ‘HyperTerminal’.
a) Select the Transfer menu
b) Select Send Text File
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CMX868 Reference Design and Demonstration Board
DE8681
c) Select the required file from the Send Text File window
1.6.5.3 Negotiation and Data Transfer
Modem negotiation (handshaking) may be aborted by pushing any key prior to entering data
transfer mode.
During data transfer mode the user can revert to on-line AT command mode by typing the
escape code sequence (+++). The escape code guard time (based on S12) must have expired
to successfully access this mode. Whilst in on-line AT command mode the board to remote
modem connection may be aborted by typing ATH0 (instructs modem to go on-hook).
Alternatively the user can enter relevant AT commands or return to data transfer mode by using
the ATO command.
The firmware only supports asynchronous data transfer.
Receiver USART overspeed settings specified in S-Register, S26, only apply to DPSK/QAM
operating modes.
Transmitter Guard Tone settings specified in S-Register, S23, only apply to DPSK/QAM
answering modes.
If the carrier is lost (during data transfer) or negotiation is aborted by the user, the firmware will
send the General Reset Command to the CMX868 device. This action will cause the DE8681
demonstration board to hang up and powersave the CMX868 device.
The data transfer firmware does not contain any retrain code. This process is sometimes
performed by modems when signal distortion or line noise is detected which may threaten data
integrity.
The receive auto equaliser function can be enabled via the S24 register. This S24 register
setting only applies to DPSK modes of operation. The CMX868 firmware for V22bis always
enables the receive auto equaliser half way through the negotiation phase.
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CMX868 Reference Design and Demonstration Board
DE8681
1.6.5.4 Example AT Commands for Hayes Optima 336 Modem (not supplied) Setup
V.22bis Protocol - AT&FB30X1Q0E1V1L0N0W2S37=6S95=42
V.22 Protocol - AT&FB0X1Q0E1V1L0N0W2S37=5S95=42
1.6.6
Example DE8681 Modem Tests
1.6.6.1 Set up DE8681 to Automatically Answer a V.22 Call from a Remote Modem
1. Select V.22 communication standard (default is V.22 bis).
Command : ATB1<CR>
2. Select the required Guard Tone setting using the AT&Gn command (default is none).
3. Enable/Disable Fixed Compromise Equalisers by writing to S-Register, S24 (default is
enabled).
4. Configure CMX868 Transmitter by writing to S-Register, S25.
5. Configure CMX868 Receiver by writing to S-Register, S26.
6. Set Automatic Answer S-Register (S0) to 5 rings.
Command : ATS0=5<CR>
The DE8681 will attempt to establish a V.22 connection when 5 rings (BT or Bell) have been
successfully detected. The CONNECT 1200 result code will be returned to the PC if a V.22
connection is successfully established. The NO CARRIER result code will be returned to the PC
if the DE8681 fails to establish a V.22 connection within the time specified in S-Register, S18.
1.6.6.2 Set up DE8681 to Manually Answer V.23 Call from a Remote Modem
1. Select V.23 communication standard (default is V.22 bis).
Command : ATB2<CR>
2. Enable/Disable Fixed Compromise Equalisers by writing to S-Register, S24 (default is
enabled).
3. Configure CMX868 Transmitter by writing to S-Register, S25
4. Configure CMX868 Receiver by writing to S-Register, S26.
5. Manually Answer V.23 Call.
Command : ATA<CR>
The DE8681 will attempt to establish a V.23 connection. The CONNECT 1200/75 result code will
be returned to the PC if a V.23 connection is successfully established. The NO CARRIER result
code will be returned to the PC if the DE8681 fails to establish a V.23 connection within the time
specified in S-Register, S18.
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CMX868 Reference Design and Demonstration Board
DE8681
1.6.6.3 Set up DE8681 to Originate V.22 bis Call to a Remote Modem
Configure DE8681 to dial out using a blind dialling method with DTMF tone duration of 150ms.
1. Select V.22 bis communication standard (default is V.22 bis).
Command : ATB0<CR>
2. Set calling characteristic to blind dial, ignoring dial and busy tones (default is ATX1).
Command : ATX1<CR>
3. Set Wait Time for Blind dialling S-Register (S6) to 5 seconds.
Command : ATS6=5<CR>
4. Set DTMF Tone Duration S-Register (S11) to 150ms.
Command : ATS11=15<CR>
5. Enable/Disable Fixed Compromise Equalisers by writing to S-Register, S24 (default is
enabled).
6. Configure CMX868 Transmitter by writing to S-Register, S25.
7. Configure CMX868 Receiver by writing to S-Register, S26.
8. DTMF Dial.
Command : ATD0165447887<CR>
The DE8681 will go off-hook and blind dial after 5 seconds. After dialling the DE8681 will
attempt to establish a V.22 bis connection. The CONNECT 2400 result code will be returned to
the PC if a V.22 bis connection is successfully established. The NO CARRIER result code will be
returned to the PC if the DE8681 fails to establish a V.22 bis connection within the time specified
in S-Register, S7.
1.6.7
Example DE8681 Device Evaluation Tests
The following information shows example text files (not supplied) that can be created by the user for
DE8681 Evaluation Mode Tests.
Description :
Command :
Instructs DE8681 to reset and powerup the CMX868 evaluation device.
[email protected][email protected]@RE0=4352<CR>
@RE0=4480 : Load 1180 Hex into CMX868 General Control Register ($E0)
@F2 : 100ms Delay
@RE0=4352 : Load 1100 Hex into CMX868 General Control Register ($E0)
General Control Register ($E0) = 1180 Hex
B15
B14
B13
B12
0
0
0
1
11.0592
Xtal
B11
0
No
LB
B10
0
Equ
Enable
B9
0
On
Hook
B8
1
Powered
Up
B7
1
Reset
B6
0
IRQN
O/P
Disabled
B5
0
B4
0
B3
B2
0
0
No IRQ Mask
B1
0
B0
0
General Control Register ($E0) = 1100 Hex
B15
B14
B13
B12
0
0
0
1
11.0592
Xtal
B11
0
No
LB
B10
0
Equ
Enable
B9
0
On
Hook
B8
1
Powered
Up
B7
0
Norm
B6
0
IRQN
O/P
Disabled
B5
0
B4
0
B3
B2
0
0
No IRQ Mask
B1
0
B0
0
The following information shows example AT commands for simple DE8681 demonstration board tests.
All tests assume the CMX868 is powered up, as shown above.
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CMX868 Reference Design and Demonstration Board
DE8681
Test 1
Description :
Command :
Instructs DE8681 to go off-hook and transmit a 1209Hz tone (Tx Gain = 0dB).
[email protected]=7685<CR>
H1 : Take DE8681 Off-Hook
@RE1=7685 : Load 1E05 Hex into CMX868 Tx Mode Register ($E1)
Tx Mode Register ($E1) = 1E05 Hex
B15
B14
B13
B12
0
0
0
1
Tx Mode = DTMF/Tones
B11
1
B10
B9
1
1
Tx Level = 0dB
B8
0
B7
0
B6
0
B5
0
B4
0
Unused
B3
B2
B1
0
1
0
Tx 1209Hz Fixed Tone
B0
1
Test 2
Description :
Command :
Instructs DE8681 to go off-hook and transmit a 1209Hz tone (Tx Gain = -10.5dB).
[email protected]=4101<CR>
H1 : Take DE8681 Off-Hook
@RE1=4101 : Load 1005 Hex into CMX868 Tx Mode Register ($E1)
Tx Mode Register ($E1) = 1005 Hex
B15
B14
B13
B12
0
0
0
1
Tx Mode = DTMF/Tones
B11
B10
B9
0
0
0
Tx Level = -10.5dB
B8
0
B7
0
B6
0
B5
0
B4
0
Unused
B3
B2
B1
0
1
0
Tx 1209Hz Fixed Tone
B0
1
Test 3
Description :
Command :
Instructs DE8681 to go off-hook and transmit a 2100Hz tone (Tx Gain = 0dB).
[email protected]=7690<CR>
H1 : Take DE8681 Off-Hook
@RE1=7690 : Load 1E0A Hex into CMX868 Tx Mode Register ($E1)
Tx Mode Register ($E1) = 1E0A Hex
B15
0
B14
B13
0
0
Tx Mode = DTMF/Tones
B12
1
B11
1
B10
B9
1
1
Tx Level = 0dB
B8
0
B7
0
B6
0
B5
0
Unused
B4
0
B3
B2
B1
1
0
1
Tx 2100Hz Fixed Tone
B0
0
Test 4
Description :
Command :
Instructs DE8681 to go off-hook and transmit V.23 continuous 1s at 75bps.
[email protected]=19995<CR>
H1 : Take DE8681 Off-Hook
@RE1=19995 : Load 4E1B Hex into CMX868 Tx Mode Register ($E1)
Tx Mode Register ($E1) = 4E1B Hex
B15
B14
B13
B12
0
1
0
0
Tx Mode = V.23 FSK 75 bps
 2004 CML Microsystems Plc
B11
1
B10
B9
1
1
Tx Level = 0dB
B8
0
B7
0
No
Guard Tone
32
B6
B5
0
0
Scrambler
Disabled
B4
B3
1
1
Sync Mode
B2
0
B1
1
Tx Cont 1’s
B0
1
UM8681/3
CMX868 Reference Design and Demonstration Board
DE8681
Test 5
Description :
Instructs DE8681 to go off-hook and transmit two DTMF digits (‘A’ then ‘B’ with
100ms duration/separation).
Command : [email protected][email protected]@[email protected]@[email protected]@RE1=7680<CR>
H1 : Take DE8681 Off-Hook
@F2 : 100ms Delay
@RE1=7709 : Load 1E1D Hex into CMX868 Tx Mode Register ($E1)
@RE1=7680 : Load 1E00 Hex into CMX868 Tx Mode Register ($E1)
@RE1=7710 : Load 1E1E Hex into CMX868 Tx Mode Register ($E1)
Tx Mode Register ($E1) = 1E1D Hex
B15
B14
B13
B12
0
0
0
1
Tx Mode = DTMF/Tones
B11
1
Tx Mode Register ($E1) = 1E00 Hex
B15
B14
B13
B12
0
0
0
1
Tx Mode = DTMF/Tones
B11
1
Tx Mode Register ($E1) = 1E1E Hex
B15
B14
B13
B12
0
0
0
1
Tx Mode = DTMF/Tones
B11
1
B10
B9
1
1
Tx Level = 0dB
B8
0
B10
B9
1
1
Tx Level = 0dB
B8
0
B10
B9
1
1
Tx Level = 0dB
B8
0
B7
0
B6
0
B5
0
B4
1
B3
1
B2
1
Tx DTMF ‘A’
B1
0
B0
1
B6
0
B5
0
B4
0
B3
0
B2
0
Tx No Tone
B1
0
B0
0
B6
0
B5
0
B4
1
B3
1
B2
1
Tx DTMF ‘B’
B1
1
B0
0
Unused
B7
0
Unused
B7
0
Unused
Test 6
Description :
Command :
Set up CMX868 for receiving DTMF, then wait for five DTMF digits.
[email protected][email protected][email protected][email protected]@[email protected]@[email protected]<CR>
@RE0=5953 : Load 1741 Hex into CMX868 General Control Register ($E0)
@RE2=7681 : Load 1E01 Hex into CMX868 Rx Mode Register ($E2)
@RE6? : Read and display contents of CMX868 Status Register ($E6)
@F7 : Wait until IRQN output goes low then read and display contents of
CMX868 Status Register ($E6)
General Control Register ($E0) = 1741 Hex
B15
B14
B13
B12
0
0
0
1
11.0592
Xtal
Rx Mode Register ($E2) = 1E01 Hex
B15
B14
B13
B12
0
0
0
1
Rx Mode = DTMF/Tones
1.6.8
B11
0
No
LB
B11
1
B10
1
Equ
Disable
B9
1
Off
Hook
B10
B9
1
1
Rx Level = 0dB
B8
1
Powered
Up
B8
0
B7
0
B7
0
Norm
B6
0
B6
1
IRQN
O/P
Enabled
B5
0
B5
0
B4
0
Detect DTMF
B4
B3
B2
B1
0
0
0
0
DTMF Detect IRQ Mask
B3
0
B2
0
B1
0
B0
1
B0
1
Trouble Shooting
Some terminal emulators have been found not to support full hardware flow control when
transferring text files. This could result in data loss when using this facility. If this problem is
experienced users should try using a different terminal emulator
To ensure successful negotiation and data transfer between the DE8681 and third party modems,
users should ensure their third party modem is configured to the correct protocol (see third party
AT command documentation).
Note, any sudden loss of the 2-wire line during data transfer will result in loss of carrier and
therefore the demonstration board will hang up and display the NO CARRIER message.
However, due to the lost carrier to hang up delay (S10), a short burst of corrupt characters (noise
generated) will be observed on the HyperTerminal window before the NO CARRIER message is
displayed. These corrupt characters can sometimes match control characters and therefore
modify HyperTerminal’s behaviour. The user is advised to restart HyperTerminal if this happens.
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CMX868 Reference Design and Demonstration Board
1.7
Performance Specification
1.7.1
Electrical Performance
DE8681
1.7.1.1 Absolute Maximum Ratings
Exceeding these maximum ratings can result in damage to the DE8681.
Supply (VDD – VSS)
Voltage on any connector pin to VSS
Current into or out of any socket modem connector pin
other than VDD, VSS, TIP and RING
Storage Temperature
Operating Temperature
Min.
-0.3
-0.3
-20
Max.
7.0
VDD + 0.3
+20
Units
V
V
mA
-40
-30
+125
+85
°C
°C
Max.
5.5
+35
Units
V
°C
1.7.1.2 Operating Limits
Correct operation of the DE8681 outside these limits is not implied.
Notes
Supply (VDD – VSS)
Operating Temperature
Min.
2.7
+10
1.7.1.3 Operating Characteristics
For the following conditions unless otherwise specified:
Evaluation Device Xtal Frequency = 11.0592MHz ±0.01% (100ppm)
VDD = 3.0V or 5.0V, Tamb = +25°C.
Notes
DC Parameters
IDD (socket modem alone - idle)
IDD (demonstration board - idle)
Notes: 1.
Min.
1
1
Typ.
12.0
30.0
Max.
Units
mA
mA
DCD, TXD, RXD, DTR, and HOOK LEDs off.
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CMX868 Reference Design and Demonstration Board
DE8681
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 any part of this product specification. Evaluation
kits and demonstration boards are supplied for the sole purpose of demonstrating the operation of CML products and are supplied
without warranty. They are intended for use in a laboratory environment only and are not for re-sale, end-use or incorporation into
other equipments. Operation of these kits and boards outside a laboratory environment is not permitted within the European
Community. All software/firmware is supplied "as is" and is without warranty. It forms part of the product supplied and is licensed
for use only with this product, for the purpose of demonstrating the operation of CML products. Whilst all reasonable efforts are
made to ensure that software/firmware contained in this product is virus free, CML accepts no resonsibility whatsoever for any
contamination which results from using this product and the onus for checking that the software/firmware is virus free is placed on
the purchaser of this evaluation kit or development board.
www.cmlmicro.com
For FAQs see: www.cmlmicro.com/products/faqs/
For a full data sheet listing see: www.cmlmicro.com/products/datasheets/download.htm
For detailed application notes: www.cmlmicro.com/products/applications/
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(UK ) Ltd
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