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Maxim > Design Support > Technical Documents > Application Notes > T/E Carrier and Packetized > APP 374
Keywords: T1, E1, J1, SCT, single chip tranceiver, SCTs, transceivers
APPLICATION NOTE 374
DS2155 vs. DS21x5y: Software and Hardware
Considerations
Dec 06, 2001
Abstract: Application note 374 describes the hardware and software considerations when upgrading an
existing DS21x5y design to use the DS2155 device. The Dallas Semiconductor DS2155 T1/E1/J1 single
chip transceiver (SCT) has a broader feature set and as such the designer must make changes in
software and hardware when migrating to the DS2155 from the DS21x5y device. Any designer who is
thinking of upgrading an existing design to use the DS2155 should read this application note. The
application note contains detailed information for software migration such as: register location changes,
how individual functions have changed from the DS21x5y to the DS2155, and which new functions are
available on the DS2155. It also covers migration for the hardware interface and covers topics such as:
interfacing with other devices, changes to the line interface, and new functions that are available in the
DS2155. In the end, the designer should have enough information to easily migrate an existing design
which uses the DS21x5y to the DS2155 device.
This note uses the device number DS21x52 to refer to both the DS21352 and DS21552. Also,
references to DS21x54 will correspond to both the DS21354 and DS21554. Whenever DS21x5y is used,
it refers to all the parts mentioned above.
1. Overview
The DS2155 is a software selectable T1, J1 or E1 Single Chip Transceiver (SCT) for short and long haul
applications. This application note intends to highlight many of the differences between the DS2155 and
the previous family of Dallas Semiconductor's SCTs. While, the DS2155 is pin compatible with previous
Dallas Semiconductor SCT's (DS2152/54, DS21352/552, & DS21552/554) the register set for the device
is much more complex. In the following pages, we will identify features from the DS21x5y devices and
pinpoint their register locations in the DS2155. Additionally, some of the new features available in the
DS2155 and what provisions need to be made existing DS21x5y designs or new designs in order to use
the DS2155 will be discussed. This note is broken into 4 sections. First, the location of DS21x52 (T1)
and DS21x54 (E1) features will be linked to the DS2155 register map. The note will then discuss some
of the new features that are available to users in all modes of operation. The last section deals with
hardware considerations when using the DS2155.
1.1 Contents
Software Considerations: DS2155 vs. DS21x52 (T1)
ID Register
Receive Control Registers
Transmit Control Registers
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