Hi all,
I am using LM3S9B96 microcontroller for my project. In My project we implemented JTAG interface with GPIO's and its working fine. Using this jtag i am able to
transfer 1MB of data in 1 min to ML605. To improve the data rate we are planning to implement JTAG interface with SPI. Is it possible to implement JTAG with
SPI?. If so how? Please provide me code if any body implemented.
Thanks & Regards,
Mah Kon
I don't have any implementation of this, but do have questions you regarding this concept.
In your implementation of a JTAG interface using GPIO, how many signals are you controlling? I presume it is at least 3, ie. TCK, TMS and TDI. Perhaps you also need TDO for programming the FPGA. As a master device on the JTAG interface and assuming my assertion is correct regarding the above signals, all 3 signals are outputs of the master device.
A SPI interface generally has 4 signals, CLK, DI, DO and sometimes CS. I could see a match between TCK and CLK. I could see a match between DO and TDI. But what SPI signal would drive TMS? TMS is an important signal as it is used with TCLK to run the JTAG state machine.
Currently, I don't see a path to implement this UNLESS you find a device with multiple data output lanes.
Brandon
Pardon - as both speed and signal number are key - should not SWD/SWO be at least a consideration?
cb1_mobile Pardon - as both speed and signal number are key - should not SWD/SWO be at least a consideration?
@Brandon- Agree with you - especially your point re: TMS(how?). AS SWD is both faster, fewer signaled than JTAG - thought it merited mention...