Transmitter Interface Configuration - Motorola MC92603 Reference Manual

Transmitter Interface Configuration

Table 2-1. MC92603 Transmitter Interface Signals (continued)
Signal Name
XCVR_x_RSEL Select redundant link
TST_1, TST_0 Test mode config inputs
MEDIA Media impedance select
XLINK_x_N/ Link serial transmit data
XLINK_x_P
rx_clock High-speed transceiver
clock
repeat_data Received repeat data
loop_back_data Loopback data
auto_neg_enable Auto-negotiation enable
2.3 Transmitter Interface Configuration
The transmitter may operate in one of eight data interface configurations as shown in
Table 2-2. The compatibility configuration pin, COMPAT, establishes operation in either
the backplane applications mode or the Ethernet compatible mode. The 10-bit interface
enable, TBIE, configuration input, determines if the internal 8B/10B encoder will be used
with uncoded input data or bypassed for a pre-encoded (coded) input data. When the DDR
configuration pin is enabled, it reduces the interface from an 8-/10-bit single data rate
interface to a 4-/5-bit double data rate interface.
The configuration signals, COMPAT and TBIE, also affect the receiver's configuration.
Data Interface Mode
Backplane 8-bit uncoded data
Backplane (4-bit reduced interface) uncoded data
Backplane 10-bit coded data
Backplane (5-bit reduced interface) coded data
Ethernet compatible GMII
Ethernet compatible RGMII
Ethernet compatible TBI
Ethernet compatible RTBI
2-4
MC92603 Quad Gigabit Ethernet Transceiver Reference Manual
Description
Transmit data on the secondary (redundant)
link
Decoded to define various test modes (see
Chapter 6, "Test Features," for details)
Indicates the impedance of the transmission
media. Low indicates 50 Ω and high indicates
75 Ω.
Differential serial transmit data output pads
Internal Signals
Internal, differential high speed clock used to
transmit and receive link data
Repeater mode, received data to re-transmit
Differential loopback transmit data
Auto-negotiate is enabled if this signal is high
and in GMII mode
Table 2-2. MC92603 Data Interface Modes
Function
COMPAT TBIE
Low Low
Low Low
Low High
Low High
High Low
High Low
High High
High High
Active
Direction
State
Input High
Input —
Input —
Output —
Input —
Input —
Output —
Input High
DDR
Low
High
Low
High
Low
High
Low
High
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