Texas Instruments MSP430x4xx - Manual (Page 486)

Scan IF Operation
24-26 Scan IF
24.2.4 Scan IF Debug Register
The Scan IF peripheral has a SIFDEBUG register for debugging and
development. Only the lower two bits should be written when writing to the
SIFDEBUG register and only
MOV instructions should be used write to
SIFDEBUG. After writing the lower two bits, reading the SIFDEBUG contents
gives the user different information. After writing 00h to SIFDEBUG, reading
SIFDEBUG shows the last address read by the PSM. After writing 01h to
SIFDEBUG, reading SIFDEBUG shows the index of the TSM and the PSM bits
Q7 - Q0. After writing 02h to SIFDEBUG, reading SIFDEBUG shows the TSM
output. After writing 03h to SIFDEBUG, reading SIFDEBUG shows which DAC
register is selected and its contents.