Datasheet
MSP430F6638, MSP430F6637, MSP430F6636
MSP430F6635, MSP430F6634, MSP430F6633
MSP430F6632, MSP430F6631, MSP430F6630
SLAS566D –JUNE 2010–REVISED AUGUST 2013
www.ti.com
Table 9. JTAG Pin Requirements and Functions
DEVICE SIGNAL DIRECTION FUNCTION
PJ.3/TCK IN JTAG clock input
PJ.2/TMS IN JTAG state control
PJ.1/TDI/TCLK IN JTAG data input, TCLK input
PJ.0/TDO OUT JTAG data output
TEST/SBWTCK IN Enable JTAG pins
RST/NMI/SBWTDIO IN External reset
VCC Power supply
VSS Ground supply
Spy-Bi-Wire Interface
In addition to the standard JTAG interface, the MSP430 family supports the two wire Spy-Bi-Wire interface. Spy-
Bi-Wire can be used to interface with MSP430 development tools and device programmers. The Spy-Bi-Wire
interface pin requirements are shown in Table 10. For further details on interfacing to development tools and
device programmers, see the MSP430(tm) Hardware Tools User's Guide (SLAU278). For a complete description
of the features of the JTAG interface and its implementation, see MSP430 Programming Via the JTAG Interface
(SLAU320).
Table 10. Spy-Bi-Wire Pin Requirements and Functions
DEVICE SIGNAL DIRECTION FUNCTION
TEST/SBWTCK IN Spy-Bi-Wire clock input
RST/NMI/SBWTDIO IN, OUT Spy-Bi-Wire data input/output
VCC Power supply
VSS Ground supply
Flash Memory (Link to User's Guide)
The flash memory can be programmed via the JTAG port, Spy-Bi-Wire (SBW), the BSL, or in-system by the
CPU. The CPU can perform single-byte, single-word, and long-word writes to the flash memory. Features of the
flash memory include:
• Flash memory has n segments of main memory and four segments of information memory (A to D) of
128 bytes each. Each segment in main memory is 512 bytes in size.
• Segments 0 to n may be erased in one step, or each segment may be individually erased.
• Segments A to D can be erased individually, or as a group with segments 0 to n. Segments A to D are also
called information memory.
• Segment A can be locked separately.
RAM Memory (Link to User's Guide)
The RAM memory is made up of n sectors. Each sector can be completely powered down to save leakage,
however all data is lost. Features of the RAM memory include:
• RAM memory has n sectors. The size of a sector can be found in Memory Organization.
• Each sector 0 to n can be complete disabled, however data retention is lost.
• Each sector 0 to n automatically enters low power retention mode when possible.
• For devices that contain USB memory, the USB memory can be used as normal RAM if USB is not required.
Backup RAM Memory
The backup RAM provides a limited number of bytes of RAM that are retained during LPMx.5 and during
operation from a backup supply if the Battery Backup System module is implemented.
There are 8 bytes of Backup RAM available on MSP430F663x. It can be wordwise accessed via the control
registers BAKMEM0, BAKMEM1, BAKMEM2, and BAKMEM3.
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MSP430F6632 MSP430F6631 MSP430F6630