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CX28395-19 参数 Datasheet PDF下载

CX28395-19图片预览
型号: CX28395-19
PDF下载: 下载PDF文件 查看货源
内容描述: 四核/ X16 /八路T1 / E1 / J1成帧器 [Quad/x16/Octal?T1/E1/J1 Framers]
分类和应用: 电信集成电路
文件页数/大小: 305 页 / 1863 K
品牌: CONEXANT [ CONEXANT SYSTEMS, INC ]
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2.0 Circuit Description  
CX28394/28395/28398  
2.4 Transmitter  
Quad/x16/OctalT1/E1/J1 Framers  
2.4.2.7 PRM Generator  
In T1 applications, Performance Report Messages (PRMs) are HDLC messages  
containing path identification and performance monitoring information. If  
automatic performance report insertion is selected [AUTO_PRM; addr 0AA], a  
performance report is generated each second and begins transmitting coincident  
with the one-second timer interrupt [ONESEC; addr 005]. The PRM is sent  
immediately if the processor sets SEND_PRM bit in the Performance Report  
Message register [PRM; addr 0AA]. All performance monitoring fields of the  
message are automatically filled in when a PRM is generated. The remaining  
PRM bit fields are application-specific and can be configured using the  
Performance Report Message register.  
For limited systems, the automatic PRM generation off-loads a significant  
portion of CPU bandwidth.  
2.4.2.8 TBOP  
Transceiver  
The Transmit Bit-Oriented Protocol (TBOP) transceiver sends BOP messages in  
T1 applications, including ESF Yellow Alarm. These messages consist of  
repeated 16-bit patterns with an embedded 6-bit codeword, as shown in this  
example:  
0xxxxxx0 11111111 (transmitted right to left)  
[543210] TBOP = 6-bit codeword  
The TBOP is configured to operate over the same channel selected by Data  
Link #1 [DL1_TS; addr 0A4]. The TBOP channel must be configured to operate  
over the FDL channel in order for TBOP to convey Priority, Command, and  
Response codeword messages according to ANSI T1.403, Section 9.4.1. The  
precedence of transmitted BOP messages with respect to current DL1 transmit  
activity is configurable using the Transmit BOP mode bits [TBOP_MODE[1,0];  
addr 0A0]. BOP messages can also be transmitted during E1 mode, although the  
16-bit codeword pattern has not currently been adopted as an E1 standard. The  
length of the BOP message [TBOP_LEN[1,0]; addr 0A0] can be set to a single  
pattern, 10 patterns, 25 patterns, or continuous.  
BOP codewords are transmitted by writing to the Transmit BOP Codeword  
[TBOP; addr 0A1]. The real-time status of the codeword transmission can be  
monitored using TBOP_ACTIVE in the BOP Status register [BOP_STAT;  
addr 0A3]. A TBOP Transmit interrupt is available in the Data Link 1 Interrupt  
Status register [ISR2; addr 009] to indicate that a codeword has begun  
transmission and the next codeword may be written to TBOP.  
2.4.3 Sa-Byte Overwrite Buffer  
There are five transmit Sa-Byte buffers [TSA4 to TSA8; addr 07B to 07F]. The  
Sa-Byte buffers insert Sa-bits into the odd frames of TS0. The entire group of 40  
bits is sampled every 16 frames coincident with the Transmit Multiframe bit  
interrupt boundary [TMF; addr 008]. Bit 0 from each TSA register is then  
inserted during frame 1, bit 1 is inserted during frame 3, bit 2 during frame 5, and  
so on, which gives the processor up to 2 ms after TMF interrupt to write new  
Sa-Byte buffer values. Transmit Sa-bits maintain a fixed relationship to the  
transmit CRC multiframe. Each of the 5 Sa-Byte transmit buffers can be  
individually enabled using the Manual Sa-Byte Transmit Enable in Transmit  
Manual Sa-Byte/FEBE Configuration register [TMAN; addr 074].  
2-46  
Conexant  
100054E