Introduction
Table 2−2. Signal Descriptions (Continued)
TERMINAL
NAME
†
I/O
DESCRIPTION
SUPPLY PINS
CV
DV
S
S
S
I
+V . Dedicated 1.5V power supply for the core CPU.
DD
DD
+V . Dedicated 3.3V power supply for I/O pins.
DD
DD
V
SS
Ground.
TCK
IEEE standard 1149.1 test clock. TCK is normally a free-running clock signal with a 50% duty cycle. The
changes on test access port (TAP) of input signals TMS and TDI are clocked into the TAP controller, instruction
register, or selected test data register on the rising edge of TCK. Changes at the TAP output signal (TDO) occur
on the falling edge of TCK.
TDI
I
IEEE standard 1149.1 test data input, pin with internal pullup device. TDI is clocked into the selected register
(instruction or data) on a rising edge of TCK.
TDO
O/Z
IEEE standard 1149.1 test data output. The contents of the selected register (instruction or data) are shifted
out of TDO on the falling edge of TCK. TDO is in the high-impedance state except when scanning of data is
in progress. TDO also goes into the high-impedance state when OFF is low.
TMS
I
I
IEEE standard 1149.1 test mode select. Pin with internal pullup device. This serial control input is clocked into
the test access port (TAP) controller on the rising edge of TCK.
TRST
IEEE standard 1149.1 test reset. TRST, when high, gives the IEEE standard 1149.1 scan system control of
the operations of the device. If TRST is not connected or driven low, the device operates in its functional
mode, and the IEEE standard 1149.1 signals are ignored. Pin with internal pulldown device.
EMU0
I/O/Z
I/O/Z
Emulator 0 pin. When TRST is driven low, EMU0 must be high for activation of the OFF condition. When TRST
is driven high, EMU0 is used as an interrupt to or from the emulator system and is defined as input/output by
way of IEEE standard 1149.1 scan system. Should be pulled up to DV with a separate 4.7-kΩ resistor.
DD
EMU1/OFF
Emulator 1 pin/disable all outputs. When TRST is driven high, EMU1/OFF is used as an interrupt to or from
the emulator system and is defined as input/output via IEEE standard 1149.1 scan system. When TRST is
driven low, EMU1/OFF is configured as OFF. The EMU1/OFF signal, when active low, puts all output drivers
into the high-impedance state. Note that OFF is used exclusively for testing and emulation purposes (not for
multiprocessing applications). Thus, for the OFF feature, the following conditions apply: TRST=low,
EMU0=high, EMU1/OFF = low. Should be pulled up to DV with a separate 4.7-kΩ resistor.
DD
†
I = Input, O = Output, Z = High-impedance, S = Supply
22
SPRS007D
November 2001 − Revised April 2004
TI [ TEXAS INSTRUMENTS ]
