DS2153Q
Reader’s Note
This data sheet assumes a particular nomenclature of the E1 operating environment. There are 32 8-bit
timeslots in E1 systems which are numbered 0 to 31. Timeslot 0 is transmitted first and received first.
These 32 timeslots are also referred to as channels with a numbering scheme of 1 to 32. Timeslot 0 is
identical to channel 1, timeslot 1 is identical to channel 2, and so on. Each timeslot (or channel) is made
up of 8 bits which are numbered 1 to 8. Bit number 1 is the MSB and is transmitted first. Bit number 8 is
the LSB and is transmitted last. Throughout this data sheet, the following abbreviations will be used:
FAS
CAS
MF
Si
CRC4
CCS
Sa
E-bit
Frame Alignment Signal
Channel Associated Signaling
Multiframe
International Bits
Cyclical Redundancy Check
Common Channel Signaling
Additional bits
CRC4 Error bits
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