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Cortina Systems LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
3.6 BGA15 Signal Descriptions
3.6
BGA15 Signal Descriptions
3.6.1
Signal Name Conventions
Signal names may contain either a port designation or a serial designation, or a
combination of the two designations. Signal naming conventions are as follows:
Port Number Only. Individual signals that apply to a particular port are designated by
the Signal Mnemonic, immediately followed by the Port Designation. For example,
Transmit Enable signals would be identified as TxEN0, TxEN1, and TxEN2.
Serial Number Only. A set of signals which are not tied to any specific port are
designated by the Signal Mnemonic, followed by an underscore and a serial
designation. For example, a set of three Global Configuration signals would be
identified as CFG_1, CFG_2, and CFG_3.
Port and Serial Number. In cases where each port is assigned a set of multiple
signals, each signal is designated in the following order: Signal Mnemonic, Port
Designation, an underscore, and the serial designation. For example, a set of three
Port Configuration signals would be identified as RxData0_0 and RxData0_1,
RxData1_0 and RxData1_1, and RxData2_0 and RxData2_1.
3.6.2
Signal Descriptions – SMII and SS-SMII Configurations
Table 39 provides the BGA15 signal descriptions.
Table 39
BGA15 Signal Descriptions (Sheet 1 of 7)
Symbol
BGA15 Ball
Designation
Type
Signal Description
SMII/SS-SMII Common Signal Descriptions
TxData0
TxData1
TxData2
TxData3
TxData4
TxData5
TxData6
TxData7
N4,
N2,
K3,
J1,
G3,
E2,
D3,
A5
I, ID
Transmit Data - Ports 0-7.
These serial input streams provide data to be transmitted to
the network. The LXT9785/LXT9785E clocks the data in
synchronously to REFCLK.
REFCLK1
REFCLK0
C3
L4
I
Reference Clock.
The LXT9785/LXT9785E always requires a 125 MHz
requirements.
SMII Specific Signal Descriptions
SYNC
K1
I, ID
SMII Synchronization.
The MAC must generate a SYNC pulse every 10 REFCLK
cycles to synchronize the SMII.
1. Type Column Coding: I = Input, O = Output, OD = Open Drain output, ST = Schmitt Triggered input, TS =
Three-State-able output, SL = Slew-rate Limited output, IP = weak Internal Pull-up, ID = weak Internal pull-
Down.
2. Switched to TPIP/N Inputs when MDIX is not active (twisted-pair, non-crossover MDI mode).
3. Switched to TPOP/N Outputs when MDIX is not active (twisted-pair, non-crossover MDI mode).