Texas Instruments ADS1254, User Manual

Page: 21 / 40

Connectors
3-5 Operation
3.3.2 J6: 3.3-V JTAG Port
This connector is used mainly during firmware development. It provides a fast
way to download firmware into the MCU, and also allows access to the MCU’s
hardware debugging features. If you have MSP430 software development
tools, you can use this port to write your own firmware for the ADS1254EVM.
This port is designed for use only with 3.3-V JTAG tools, such as those
provided by TI for use with the MSP430. If you attempt to use 5-V JTAG
tools with this port, you permanently damage the MSP430, as it is not 5-V
tolerant.
Table 3−3. J8: 3.3-V JTAG Port
Pin Num-
ber Pin
Symbol Signal Name Direction
(at board) Function
1 TDI/TDO Test data in/out Output JTAG TDO port (see JTAG standard)
2 VCCTOOL Power from JTAG
adapter Power JTAG adapter−provided power supply
(not used on ADS1254EVM)
3 TDI/VPP Test data in/pro-
gramming voltage Input Used as a test data input, and for blowing
the security fuse
4 VCCLOCAL Power sense
from board Output High rail from board; used for signal sense
when board is using its own power supply
during programming
5 TMS Test mode select Input JTAG test mode select pin (see JTAG
standard)
6 NC Not connected − Not used
7 TCK Test clock Input JTAG serial clock input (see JTAG
standard)
8 NC Not connected − Not used
9 GND Ground Power Signal ground
10 NC Not connected − Not used
11 RST/NMI Reset/non-mask-
able interrupt Input MCU reset line
12 NC Not connected − Not used
13 NC Not connected − Not used
14 NC Not connected − Not used