Bt8960EVM Hardware User’s Guide
Bt8960
Interface Descriptions
Bt8960EVM Hardware User’s Guide
8
Conexant
100188B
Conexant Proprietary and Confidential
RS-232 Interface (J4)
Connector J4 provides an RS-232 connection to the 80C32 microprocessor. The TX, RX and GND
are the only RS-232 signals utilized for this connection. TX and RX are labeled on the line card
PCB silk-screen.
Digital Data Interface (J5, J6, J7, J8)
Four BNC connectors are provided to connect the raw digital data and clocks to be transmitted and
received over the line to the Bt8960. These connectors are buffered through an HCT244 buffer to
protect the Bt8960 from improper connections and to provide extra drive strength for coax cables.
All outputs include a source resistance of 50 ohms to prevent ringing. The TDATA IN input (J8) is
pulled up to 1 Kohm to prevent ringing while also providing a high enough input impedance so it
can be driven by a typical CMOS driver. After these signals are buffered, they connect to the channel
unit interface section of the Bt8960. See the Bt8960 datasheet for details on the channel unit
interface timing and functionality. Test points are provided for all of the Bt8960 channel unit
interface signals so that the signals can be connected to a customized framer if desired. Prototype
space is also available on the line card for this purpose.
Test Points
A variety of test points are included on the Bt8960 to accommodate test measurements and to
provide solder points for prototyping.
lists all of the test points on the Bt8960 line card along
with their associated signal names. These test points have been numbered in an orderly fashion on
the 8960 line card so that they are easy to locate.
Table 2 8960 Line Card Test Point
Test Point Name
Signal Name
TXP
Transmit (positive)
TXN
Transmit (negative)
TP1
SMON
TP2
RST*
TP3
HCLK
TP4
XOUT
TP5
TIP / R46
TP6
TIP (line side)
TP7
TIP (circuit side)
TP8
Split Transformer / TIP
TP9
BCLK (buffered)
TP10
Split Transformer / RING
TP11
RING / R45
TP12
RING
