CH2056A ET Cermetek Microelectronics, CH2056A ET Datasheet - Page 8

• Manufacturer Part Number: CH2056A ET
• Manufacturer: Cermetek Microelectronics

Specifications of CH2056A ET

• Main Category: Single Chip
• Power Supply Type: Analog
• Operating Supply Voltage (typ): 3.3/5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Lead Free Status / RoHS Status: Not Compliant

Cermetek Microelectronics, Inc.
On power up, or when reset is initiated either by the
ATZ<CR> command or by the RST pin, the modem
will reconfigure to its default state with the line carrier
modulation speed set to:
1. 14.4kbps for the CH1794A.
2. 33.6kbps for the CH1799A.
3. 57.6kbps for the CH2056A.
If desired, any speed, error correction, or data
compression method available on the HS Modem can
be locked in, using the AT\Nn and/or AT+MS
commands.
Training the Modem. Each modem must be trained
to match the host DTE speed and parity so that it is
able to recognize serial asynchronous commands sent
to it by the DTE.
The DTE must retrain the modem each time a reset
pulse is applied on RST or after a RESET serial
command has been issued.
STATUS MESSAGES AND RESULTS CODES
A result code is issued by the HS Modem to the DTE
for all commands executed by the HS Modem except
dialing commands. Further, various activities on the
PSTN are also signaled to the DTE by the HS Modem.
All result codes have either a terse, short form version
(which is identified by a number followed by a <CR>)
or a verbose long form English-like message version
(which is preceded and terminated with a <CR> and
<LF>).
The user may suppress certain subsets of the non-
extended result codes.
selecting subsets of the result code set using the
ATXn command, where n=0, 1, 2 or 3. Optionally, the
user may specify an extended set of results codes
(codes above 35) by setting Register S95. See the
detailed description of results codes in Table 5.
All AT commands, other than dialing commands, will
be responded to with either an OK (short form result
code 0) or the command is valid or accepted, or with
an ERROR (result code 4) if the command is not
recognized. The detail contained in the error result
codes signaled to the DTE depends on the level of
message suppression employed by the user. As can
be seen from Table 5, specifying X4 allows the HS
Modem to utilize the entire range of non-extended
messages, whereas X0 suppresses all but the very
basic result codes. Most of the result codes allowed
under X1, X2 and X3 are considered call progress
status codes and, in practice, are suppressed except
for
recommended that the non-extended result codes be
used in all cases.
2007 Cermetek Microelectronics, Inc.
the
case
of
debugging
This is accomplished by
activities.
It
is
Page 8
It should be noted that the default connect result codes
9-20 indicate DTE connection speed, not Carrier Line
DCE speed.
maximum speed of 19.2kbps (result code 16). The
CH1799A will connect at a maximum DTE speed of
38.4kbps (result code of 17) and the CH2056A will
connect at a maximum speed of 57.6kbps (result code
18) unless the DTE is forced to a higher speed by
selection of data compression.
maximum DTE to modem speed is 230.4kbps (result
code20).
Extensions to the basic result code set may be
specified by Register S95, which allows for the use of
result codes 40-64, 165-194.
LEASED LINE OPTION
The
L/CH2056AR-L is a leased line version of the
CH1799A. Whereas the CH1799A requires an active
voltage bearing or wet PSTN line for normal
operations (typically, 48VDC on-hook line voltage), the
CH179XA-L/CH2056A-L
L/CH2056AR-L is designed to operate over a non-
voltage bearing or dry line.
The
L/CH2056AR-L will only operate properly on a dry line.
Damage will occur if used on a wet line.
CH179XA-L/CH2056A-L
L/CH2056AR-L does not support ring detect but does
support
Application Note # 116 for examples and instructions
to establish a connection over a leased dry line wire
pair. Note that the length of the leased line is limited
to 20,000 feet.
recommended in Figure 6B and in Cermetek
Application Note # 126.
requirements for FCC Part 68 compliance. The User
is responsible to ensure that FCC Part 68 compliance
is maintained.
As an alternative, the CH1799A will operate on a
leased line if the line is made wet by application of a
DC voltage. Refer to Cermetek Application Note #
114
Result codes 53-64 are supported by the CH1799A
and CH2056A.
supported by the CH2056A. To obtain a detailed
status report for a given modem communication
configuration, use the AT\V1 command. Executing
this command at setup will cause the modem to
connect and return a message consisting of <DTE
speed> <modulation> <error protocol> <line speed
of connection>.
.
CH179XA/2056A High Speed Family of Ultra Small Modems
CH179XA-L/CH2056A-L
CH179XA-L/CH2056A-L
off-hook
Hence, a CH1794A will connect at a
IMPORTANT NOTE
Document No. 607-0020 Revision B (01/07)
Result codes 165-194 are only
control.
Use PSTN line protection as
and
and
Follow all applicable
Refer
and
and
In this case, the
to
CH179XAR-
CH179XAR-
CH179XAR-
CH179XAR-
Cermetek
The