MOTOROLA
Chapter 3. Receiver
3-5
Functional Description
3.3
Functional Description
The MC92603 receiver receives differential data in one of two operating ranges. It may be
operated in full rate range with a maximum data rate of 1.0 Gbps (1.25 Gigabaud) or at
half-rate at 500 Mbps (0.625 Gigabaud). The operating range is determined by the state of
the HSE input and the frequency of the reference clock, see Table 5-1.
Transmitted data is recovered using an oversampled transition tracking method. The
received serial data is accumulated into 10-bit characters. The 10-bit characters are
forwarded to the 8B/10B decoder where the original data is obtained. Alternately, the
decoder can be bypassed, and the 10-bit character is forwarded to the receiver interface in
the 10-bit interface (TBI) mode.
The receiver provides for byte (character) alignment. Alignment assures that the byte,
presented at the input of the transmitter is preserved when it is presented by the receiver.
Optionally, alignment may be disabled if in the backplane 10- or 5-bit mode.
The code group alignment is obtained by aligning to COMMA (K28.1, K28.5, or K28.7)
code groups. Alignment is achieved when four COMMA code groups with the same
alignment, are detected.
NOTE
The COMMA code group (K28.7) should be used carefully
since the combination of this code group with some adjoining
code groups will yield false COMMA alignment.
The receiver also provides for word synchronization (this feature is available only in
‘backplane’ operating modes). In this mode, all of the receivers are being used
cooperatively to receive 32-bit (40-bit in TBI mode) words. Word synchronization ensures
that the receivers present the 4 bytes of a word simultaneously.
At the receiver interface is where the received bytes and status codes are obtained. The
receiver interface has several modes of operation and timing that allow it to be used in a
variety of applications. The following sections provide a detailed description of the receiver
and its modes of operation.
3.3.1
Input Amplifier
The input amplifiers connect directly to the link input pads RLINK_x_P and RLINK_x_N.
It is a differential amplifier with an integrated analog multiplexer for loopback testing. Link
termination resistors are integrated with the amplifier. The termination resistance is either
100 or 150
Ω
differential depending on the state of the MEDIA configuration input pin.
Termination resistance is 100
Ω
(differential) when the MEDIA is low and 150
Ω
(differential) when the MEDIA is high.
Summary of Contents for MC92603
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