参数资料
型号: PEF2080
厂商: SIEMENS AG
英文描述: S/T Bus Interface Circuit(SBC)
中文描述: S / T的总线接口电路(SBC)的
文件页数: 15/74页
文件大小: 2620K
代理商: PEF2080
Semiconductor Group
16
Functional Description
Digital Functions
A DPLL circuitry working with a frequency of 7.68 MHz
±
100 ppm serves to generate the 192-kHz
line clock from the reference clock delivered by the network and to extract the 192-kHz line clock
from the receive data stream.
The 7.68-MHz clock may be generated with the use of an external crystal between pins XTAL1 and
XTAL2. It may also be provided by an external oscillator, in which case XTAL2 is left unconnected.
The “Control” block includes the logic to detect layer-1 commands and to communicate with
external layer-1 or layer-2 devices via the IOM interface.
An incorporated finite state machine controls ISDN layer-1 activation/deactivation.
The D-channel access procedure according to CCITT I.430 including priority management is fully
implemented in the SBC. When used as an S-bus master in a multipoint configuration, the device
generates the echo bits necessary for D-channel collision detection. In the NT-mode, moreover, the
echo channel may be made externally available through an auxiliary pin and thus “intelligent NT’s”
(star configuration) may be implemented.
In terminal applications (TE) the Q channel as specified by I.430 is supported (stepping A6 and up.
The SBC sends a binary one in F
A
-bit position to allow another terminal to use the extra
transmission capacity.)
The buffer memory serves to adapt the different bit rates of the S and the IOM interface. In addition,
in trunk line applications it absorbs the possible deviation between two system clocks, according to
CCITT Q.503 (slip detection).
2.2
Operating Modes
The operating modes are determined by pin strapping on pins M0 to M2. The four basic operating
modes are: TE, NT, LT-S, LT-T.
In three of these operating modes, the IOM may be programmed to function in the IOM-1 mode, in
the IOM -2 mode or in the inverted mode. To see which IOM timing mode is applicable in the four
basic operating modes, refer to
table 1
.
In
table 1
, the functions of the operating mode specific pins are given: these pins are DCL (IOM
interface data clock, input/output), FSC (IOM interface frame sync, input/output), CP (auxiliary
clock/test pin), and X0 to X3.
Depending on the selected mode, pins CP, X2 and X1 provide auxiliary clocks, either asynchronous
or synchronous to the S-interface:
These auxiliary clocks may be used to drive, e.g. a codec filter, or a microprocessor system (TE
applications).
3840 kHz
2560 kHz
1280 kHz
clocks derived from the 7680-kHz crystal
1536 kHz
512 kHz
clocks synchronized to S interface
相关PDF资料
PDF描述
PEF22554 Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
PEF22554E Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
PEF22554HT Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
PEF2256 Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
PEF2256E Ultraframer DS3/E3/DS2/E2/DS1/E1/DS0
相关代理商/技术参数
参数描述
PEF2080-N 制造商:INFINEON 制造商全称:Infineon Technologies AG 功能描述:S/T Bus Interface Circuit(SBC)
PEF2091 制造商:INFINEON 制造商全称:Infineon Technologies AG 功能描述:ICs for Communications(ISDN Echocancellation Circuit)
PEF2091F 制造商:未知厂家 制造商全称:未知厂家 功能描述:?ISDN Echocancellation Circuit - 2B1Q Code?
PEF2091FV5.3 制造商:INFINEON 制造商全称:Infineon Technologies AG 功能描述:ICs for Communications(ISDN Echocancellation Circuit)
PEF2091HV5.3 制造商:INFINEON 制造商全称:Infineon Technologies AG 功能描述:ICs for Communications(ISDN Echocancellation Circuit)