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PM7344-RI 参数 Datasheet PDF下载

PM7344-RI图片预览
型号: PM7344-RI
PDF下载: 下载PDF文件 查看货源
内容描述: [Telecom Circuit, 4-Func, CMOS, PQFP128, 14 X 20 MM, 2.70 MM HEIGHT, 0.50 MM PITCH, PLASTIC, MQFP-128]
分类和应用: 网络接口
文件页数/大小: 293 页 / 1101 K
品牌: PMC [ PMC-SIERRA, INC ]
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PM7344 S/UNI-MPH  
DATA SHEET  
PMC-950449  
ISSUE 6  
MULTI-PHY USER NETWORK INTERFACE  
A Saturn Compatible Interface (SCI-PHYTM) FIFO is provided. This synchronous  
FIFO accepts a read clock (RFCLK) and read enable signal from the MPHY  
block. The receive FIFO output bus is tristated when the read enable is inactive.  
The interface indicates the start of a cell (RSOC) and the receive cell available  
status (RCA) when data is read from the receive FIFO (using the rising edges of  
RFCLK while read enable is active). The RCA status changes from available to  
unavailable when the FIFO is 4 byte read accesses away from being empty (or  
when the FIFO is empty, when REMPTY4 is logic 0).  
This RXFF indicates FIFO overruns using a maskable interrupt and register bits.  
The FIFO is reset on FIFO overrun, causing up to 4 cells to be lost.  
9.18 Transmit ATM Cell Processor (TXCP)  
The Transmit Cell Processor (TXCP) Block integrates circuitry to support ATM  
cell payload scrambling, header check sequence (HCS) generation, and  
idle/unassigned cell generation.  
The TXCP scrambles the cell payload field using the self synchronizing  
scrambler with polynomial x43 + 1. The header portion of the cells is not  
scrambled. Note that cell payload scrambling is optional in the S/UNI-MPH.  
The HCS is generated using the polynomial, x8 + x2 + x + 1. The coset  
polynomial x6 + x4 + x2 + 1 is added (modulo 2) to the calculated HCS octet as  
required by the ATM Forum UNI specification, and ITU-T Recommendation I.432.  
The resultant octet optionally overwrites the HCS octet in the transmit cell.  
When the transmit FIFO is empty, the TXCP inserts idle/unassigned cells. The  
idle/unassigned cell header is fully programmable using five internal registers.  
Similarly, the 48 octet information field is programmed with an 8 bit repeating  
pattern using an internal register. The TXCP accumulates the number of  
transmitted assigned cells in a saturating counter.  
For T1/E1 formats, the cell octets are byte aligned with the transmission  
overhead (the framing bit for the T1 format, and timeslots 0/16 for the E1 format).  
For arbitrary bit rate interfaces, the cell octets are optionally aligned to the  
overhead indication signal (TOHI).  
9.19 Transmit ATM 4 Cell FIFO (TXFF)  
The Transmit FIFO (TXFF) provides FIFO management and the S/UNI-MPH  
transmit cell interface. The transmit FIFO can hold up to four cells. The FIFO  
depth may be programmed to one, two, three, or four cells. The FIFO provides  
the cell rate decoupling function between the transmission system physical layer  
and the ATM layer.  
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE  
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