- 您現(xiàn)在的位置：買賣IC網 > PDF目錄383876 > T7256A Compliance with the New ETSI PSD Requirement PDF資料下載
參數(shù)資料
| 型號： | T7256A |
| 英文描述： | Compliance with the New ETSI PSD Requirement |
| 中文描述： | 符合新的ETSI PSD的要求 |
| 文件頁數(shù)： | 16/116頁 |
| 文件大小： | 1056K |
| 代理商： | T7256A |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁當前第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁
Data Sheet
January 1998
T7256 Single-Chip NT1 (SCNT1) Transceiver
12
Lucent Technologies Inc.
Functional Overview
(continued)
When the T7256 is powered on and there is no activity
on the S/T- or U-interfaces (i.e., no pending activation
request), it automatically enters a low-power IDLE
mode in which it consumes an average of 35 mW.
This mode is exited automatically when an activation or
U maintenance request occurs from either the micro-
processor or the S/T- or U-interfaces. The T7256 pro-
vides a board-level test capability that allows functional
verification. Finally, an LED driver output indicates the
status of the device during operation.
U-Interface Frame Structure
Data is transmitted over the U-interface in 240-bit
groups called U frames. Each U frame consists of an
18-bit synchronization word or inverted synchronization
word (SW or ISW), 12 blocks of 2B+D data (216 bits),
and six overhead bits (M bits). A U-interface super-
frame consists of eight U frames grouped together. The
beginning of a U superframe is indicated by the
inverted sync word (ISW). The six overhead bits (M1—
M6) from each of the eight U frames, when taken
together, form the 48 M bits. Figure 4 shows how U
frames, superframes, and M bits are arranged.
Of the 48 M bits, 24 bits form the embedded operations
channel (eoc) for sending messages from the LT to the
NT and responses from the NT to the LT. There are two
eoc messages per superframe with 12 bits per eoc
message (eoc1 and eoc2). Another 12 bits serve as U-
interface control and status bits (UCS). The last 12 bits
form the cyclic redundancy check (CRC) which is cal-
culated over the 2B+D data and the M4 bits of the pre-
vious superframe. Figure 5 and Table 2 show the
different groups of bits in the superframe.
5-2476 (C)
Figure 4. U-Interface Frame and Superframe
U1
U2
U3
U4
U5
U6
U7
U8
U-INTERFACE M BITS [48]
U-FRAME SPAN = 1.5 ms
U-SUPERFRAME SPAN = 12 ms
ISW[18]
(2B+D) x 12 [ 216 bits]
M[6]
相關PDF資料 |
PDF描述 |
|---|---|
| T7288 | CEPT/E1 Line Interface(CEPT/E1 線接口) |
| T7290A | DS1/T1/CEPT/E1 Line Interface(DS1/T1/CEPT/E1 線接口) |
| T7295-1 | E3 Integrated Line Receiver(E3 集成線接收器) |
| T7295-6 | DS3/SONET STS-1 Integrated Line Receiver(DS3/SONET STS-1 集成線接收器) |
| T7296 | Integrated Line Transmitter(集成PCM線傳送器) |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| T7257 | 制造商:TE Connectivity 功能描述: |
| T-726 | 制造商:RHOMBUS-IND 制造商全稱:Rhombus Industries Inc. 功能描述:ADSL Line Interface Transformers |
| T7263 | 制造商:TE Connectivity 功能描述: |
| T7263A | 制造商:Toshiba America Electronic Components 功能描述:T7263A |
| T7264 | 制造商:TE Connectivity 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復。