SLAU320AJ July 2010 – May 2021
This macro loads a 16-bit word into the JTAG data register (DR) (in the MSP430 devices, a data register is 16 bits wide). The data word is shifted, most significant bit (MSB) first, into the TDI input of the target MSP430 device. Each bit is captured from TDI on a rising edge of TCK. At the same time, TDO shifts out the last captured and stored value in the addressed data register. A new bit is present at TDO with a falling edge of TCK. TCLK should not change state while this macro is executing. Figure 2-4 shows how to load a 16-bit word into the JTAG DR and read out a stored value through TDO.