Cermetek Microelectronics, Inc.
High Speed Internet Modem Family
2005 Cermetek Microelectronics, Inc.
Page 5
Document No. 607-0017-01 Revision A (05/05)
Figure 2 contains a schematic drawing illustrating the
interconnectivity of the various functional blocks
comprising the CH2165 iModem products.
Each iModem performs the following internet
connectivity functions automatically:
1. Dials local POP and Connects to ISP.
2. Authenticates user ID and logs onto the internet.
3. Sends (or Retrieves) email to (from) the server
address/name specified using the ISP’s SMTP
(POP3) Mail Server.
4. Leaves ISP session active after all data is sent until
terminated by user.
Control of the internet capabilities of the iModem are
initiated and controlled by a system level host
processor. Refer to Table 2 for a complete set of pin
descriptions.
When not utilized in the internet connectivity role, the
iModem will function as a standard analog modem.
KEY FEATURE
The user has complete control of the level of
autonomy the iModem exercises in the user’s
application. This is a unique feature of Cermetek’s
iModem products.
µP Controller.
The µP controller performs the required
internet operations by interpreting each specific
@T
®
command and executing the appropriate internet
commands. The necessary internet protocol firmware
is resident in flash ROM. The
@T
®
commands function
as an extension to the industry standard Hayes AT
command set.
Internal Modem.
The internal modem is used to
establish a data connection with the ISP. The CH2165
contains a V.90 internal modem. The internal modem
can be controlled with Hayes AT commands and is
compatible with industry standard communication
software. Refer to Cermetek publication, AT
Commands and S-Registers, for a more detailed
discussion of the Hayes AT commands supported by
the iModem product family.
When operating in standard analog modem mode, the
maximum Data Terminal Equipment (DTE)/Host system
communication speed is established by the maximum
speed available from the DTE/Host and is not limited by
the iModem product.
IMPORTANT NOTICE
AS DELIVERED FROM THE FACTORY, all
@T
®
command communication between the CH2165
iModem and the host processor is conducted over the
serial interface at 19.2kbps.
CH21XX DTE Speed.
AS DELIVERED FROM THE
FACTORY, the CH2165 iModem will only communicate
with the DTE at 19.2 kbps. However, the user may
modify the DTE speed with the appropriate
@T
®
commands. Application Note # 325,
@T
®
Command
Set Description and Usage For CH2165. When the
user changes the DTE communication speed to any
speed other than the default value set of the factory, the
user must ensure that the DTE supports the speed
selected. Failure to do so could adversely affect
communication with the iModem device or, worst-case,
disable communication with the internal µP controller.
Refer to Application Note # 158, Cermetek iModem
Caveats and Definitions, for a more detailed discussion
of this issue.
Refer to Cermetek’s High Speed Modem and FAX
Family product data sheet for a complete Description of
the internal modem’s capabilities and functions.
Serial Host Interface Buffer.
The iModem utilizes a
serial V.24 EIA 232-E 5V interface to communicate with
the internal modem and to communicate with the
internal µP.
Telephone Line Interface or DAA.
The iModem
family includes a unique low distortion DAA designed
for optimal performance over all PSTN line conditions
thereby achieving the most reliable and best
performance PSTN connections.
The CH2165 iModem is designed to meet North
American telephone standards as set by FCC Part 68
(USA) and Industry Canada CS-03 Part I (Canada).
Each iModem product is shipped from the factory with
an FCC label indicating the FCC registration number
and ringer equivalent. The PSTN line interface is
UL1950 and CSA listed. Consequently, the iModem
family of products satisfies U.S. and Canadian
requirements, and will meet other international approval
agency requirements that specify these levels of
isolation.
IMPORTANT NOTICE
If the user wants to change the DTE/Host
communication speed to any speed other than the
factory set speed of 19.2kbps for the CH2165, the
user must first change the DTE speed of the iModem
using the appropriate all
@T
®
commands before
changing the DTE/Host speed. Refer to Application
Note # 158, Cermetek iModem Caveats and
Definitions, for a more detailed discussion of this
issue.
