MSP430FR6979 Datasheet, PDF (141/163 Pages) Texas Instruments – Mixed-Signal Microcontrollers

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Important to connect
V_CC
J1 (see Note A)
J2 (see Note A)
R1
47 kΩ
See Note B
VCC TOOL
VCC TARGET
JTAG
2
1 ^TDO/TDI
4
3
6
5
8
7 ^TCK
10
9 ^GND
12
11
14
13
C1
2.2 nF
See Note B
MSP430FR6979, MSP430FR69791, MSP430FR6977
MSP430FR6928, MSP430FR6927, MSP430FR69271
SLAS797A – AUGUST 2014 – REVISED MARCH 2015
MSP430FRxxx
AVCC/DVCC
RST/NMI/SBWTDIO
TEST/SBWTCK
AVSS/DVSS
A. Make connection J1 if a local target power supply is used, or make connection J2 if the target is powered from the
debug or programming adapter.
B. The device RST/NMI/SBWTDIO pin is used in 2-wire mode for bidirectional communication with the device during
JTAG access, and any capacitance that is attached to this signal may affect the ability to establish a connection with
the device. The upper limit for C1 is 2.2 nF when using current TI tools.
Figure 7-4. Signal Connections for 2-Wire JTAG Communication (Spy-Bi-Wire)
7.1.4 Reset
The reset pin can be configured as a reset function (default) or as an NMI function in the Special Function
Register (SFR), SFRRPCR.
In reset mode, the RST/NMI pin is active low, and a pulse applied to this pin that meets the reset timing
specifications generates a BOR-type device reset.
Setting SYSNMI causes the RST/NMI pin to be configured as an external NMI source. The external NMI is
edge sensitive, and its edge is selectable by SYSNMIIES. Setting the NMIIE enables the interrupt of the
external NMI. When an external NMI event occurs, the NMIIFG is set.
The RST/NMI pin can have either a pullup or pulldown that is enabled or not. SYSRSTUP selects either
pullup or pulldown, and SYSRSTRE causes the pullup (default) or pulldown to be enabled (default) or not.
If the RST/NMI pin is unused, it is required either to select and enable the internal pullup or to connect an
external 47-kΩ pullup resistor to the RST/NMI pin with a 2.2-nF pulldown capacitor. The pulldown
capacitor should not exceed 2.2 nF when using devices with Spy-Bi-Wire interface in Spy-Bi-Wire mode or
in 4-wire JTAG mode with TI tools like FET interfaces or GANG programmers.
See the MSP430FR58xx, MSP430FR59xx, MSP430FR68xx, and MSP430FR69xx Family User's Guide
(SLAU367) for more information on the referenced control registers and bits.
7.1.5 Unused Pins
For details on the connection of unused pins, see Section 4.6.
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Applications, Implementation, and Layout 141
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Product Folder Links: MSP430FR6979 MSP430FR69791 MSP430FR6977 MSP430FR6928 MSP430FR6927
MSP430FR69271