PMC-Sierra, Inc.
STANDARD PRODUCT
PM5945 -UTP5
PMC-940202 ISSUE 2. APRIL 7, 1995
APP_SAPI_UTP5
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mode of operation on the receive side of the S/UNI device. In the normal mode of
operation (good incoming signal) the S/UNI device is in the serial mode and accepts
clock and data from the high speed interface (RSER is high). In loss of signal
condition, the S/UNI device is switched to the parallel mode and accepts data from
the PICLK and PIN[7:0] inputs. The POCLK is switched to generate the 19.44 MHz
PICLK. This technique also guarantees that the S/UNI will generate a LOS
indication when the TWISTER loses incoming signal. This is achieved due to the
CY7B951 not squelching the data in a loss of signal condition.
The transmit line interface consists of the S/UNI PECL transmit outputs that are
buffered by the CY7B951 and then connected to the TWISTER's transmit section.
Outgoing data on TXO+/- pins is coupled to the line via a 1:1 turns ratio transformer.
The receive line interface consists of a 1:1.4 step-up transformer coupling data from
the UTP5 cables to the RXI+/- pins of the TWISTER. The received datastream is
equalized and output by the TWISTER to the CY7B951 which recovers the data and
clock and relays the them to the S/UNI via its PECL differential outputs.
An 8 pin 8 position RJ45 modular jack is used to connect to the UTP5 cables. The
unused pairs of cables are terminated via a resistor network to a common mode
termination point. The center taps of the transformers are also terminated to the
same point.
The S/UNI is configured for bit serial operation. The 155.52 MHz transmit clock
source is synthesized by the CY7B951 from a 19.44 MHz oscillator. The receive
clock and data recovery is supplied by the Cypress CY7B951 device. If the loop
back select is enabled on the CY7B951 the transmit data is muxed into the receive
PLL and the recovered clock and data are fed back to the S/UNI device. The S/UNI
can also be configured for loop time operation. When configured for loop time
operation, only a receive clock and data recovery device is required.
UTOPIA Identification ROM
The upper 32 bytes of the address space is used by the UTOPIA identification ROM
to hold the interface configuration information.
Table 1: Standard ROM Address and Content
Address
0x1E0
Function
Address
Function
Protocol Type
Media Type
Capability
0x1E4-0x1EB
0x1EC-0x1EF
0x1F0-0x1FF
64 or 48-bit Address
Reserved
0x1E1
0x1E2-0x1E3
Manufacturer ID, Version
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5
PMC [ PMC-SIERRA, INC ]
