
MT9072
Advance Information
24
198
C5
RESET
I
Reset.
When zero, all eight framers of the MT9072 are in a reset
condition where all registers are set to their default values. When one,
all eight framers of the MT9072 operate normally where all registers
may be programmed by the external processor. A valid reset condition
requires this input to be held low for a minimum of 100ns. This input
should be set to zero during initial power up, then set to one.
199
A5
TAIS
I
Transmit Alarm Indication Signal.
When zero, all eight framers of
the MT9072 transmit an all ones signal (AIS) at the TPOS and TNEG
output pins. When one, all eight framers of the MT9072 transmit data
normally. This input is typically set to zero during initial power up, then
set to one.
200
B5
TxMF
I
Transmit Multiframe Boundary.
This pin accepts a frame pulse that
sets the multiframe boundary for the framer transmitters. The device
will generate its own multiframe boundary if this pin is held high. The
TxMF pin is held high in most applications. This input is common for all
eight framers, and is enabled on a per framer basis with a control
register bit. Operation is identical in 2.048 Mbit/s and 8.192 Mbit/s
modes.
In T1 mode the frame pulse applied to this pin sets the transmitted D4/
ESF multiframe boundary. The falling edge of this frame pulse
identifies basic frame 0 on the ST-BUS data stream (DSTi). This input
is enable with control bit TxMFSEL (Address YF1). See Figure 34.
In E1 mode the frame pulse applied to this pin sets the transmitted
channel associated signaling (CAS) multiframe boundary or the
transmitted CRC-4 multiframe boundary. The falling edge of this frame
pulse identifies basic frame 0 on the ST-BUS data stream (DSTi) of the
16 frame multiframe. This input is enabled with control bit MFBE
(Address Y02). See Figure 53.
201
A4
RSV
--
This pin should be tied low.
202
B4
RSV
--
This pin should be tied low.
203
C4
RSV
--
This pin should be tied low.
204
A3
TDI
IPu
Test Data Input.
One of five signals (TDI, TDO, TMS, TCK & TRST)
making up the Test Access Port (TAP) of the IEEE 1149.1-1990
Standard Test Port and Boundary-Scan Architecture. The TAP
provides access to test support functions built into the MT9072. The
TAP is also referred to as a JTAG (Joint Test Action Group) port.
205
A2
TDO
OH
Test Data Output.
Depending on the sequence previously applied to
the TMS input, the contents of either the instruction register or data
register are serially shifted out towards the TDO. The data out of the
TDO is clocked on the falling edge of the TCK pulses. When no data is
shifted through the boundary scan cells, the TDO driver is set to a high
impedance state. See the pin description for TDI and the section on
JTAG.
Pin Description (continued)
Pin #
Name
Type
Description (see Notes 1 to 7)
LQFP
LBGA