JTAG USER1 register on Max 10

[Tom_B]

We instantiated a JTAG USER1 register in a Max II device by using this built-in component (VHDL):

component maxii_jtag
PORT (
tms : in std_logic;
tck : in std_logic;
tdi : in std_logic;
tdouser : in std_logic;
tdo : out std_logic;
tmsutap : out std_logic;
tckutap : out std_logic;
tdiutap : out std_logic;
shiftuser : out std_logic;
clkdruser : out std_logic;
updateuser : out std_logic;
runidleuser : out std_logic;
usr1user : out std_logic);
end component;

We just needed a couple more lines of VHDL code to instantiate our USER1 register.

We are converting it to a Max 10 device, but this component does not exist. How do we do this (simply) with a Max 10 device?

[Ash_R_Intel]

Hi Thomas,

The Virtual JTAG IP can help you. Here is the user guide.

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug_virtualjtag.pdf

Regards.

[Tom_B]

The problem is that I'm using a very small CPLD devices, and this 'virtual jtag' function adds a lot of unnecessary logic that eats up space I need in the device.  I'm trying to do something really simple in a very simple device.  I'm just trying to add a USR register. Nothing else.

The 'component maxii_jtag' gave me exactly what I wanted, even signals the 'virtual jtag' function doesn't give, such as a clock for shifting the user register (clkdruser). I could create this from the 'virtual jtag' outputs, but that is even more logic I'd have to add. 

Using the 'virtual jtag' function makes the code more complicated than it needs to be and adds a bunch of extra logic I don't need or want.

Almost every CPLD/FPGA has a function like the "component maxii_jtag". All of these exist:

component arriaii_jtag
component arriaiigz_jtag
component arriav_jtag
component arriavgz_jtag
component cyclone_jtag
component cyclone10lp_jtag
component cycloneii_jtag
component cycloneiii_jtag
component cycloneiiils_jtag
component cycloneiv_jtag
component cycloneive_jtag
component cyclonev_jtag
component fiftyfivenm_jtag
component maxii_jtag
component maxv_jtag
component stratix_jtag
component stratixgx_jtag
component stratixii_jtag
component stratixiigx_jtag
component stratixiii_jtag
component stratixiv_jtag
component stratixv_jtag
component twentynm_jtagblock
component twentynm_jtag
component twentynm_hps_interface_jtag

Only component max10_jtag seems to be missing--the very one I want!

[Ash_R_Intel]

Please use the fiftyfivenm_jtag component for MAX 10.

Reference: https://www.intel.com/content/dam/altera-www/global/en_US/uploads/5/5f/MAX10_JTAG_Secure_Unlock_UG.pdf

Regards

[Ash_R_Intel · Accepted solution]

Please use the fiftyfivenm_jtag component for MAX 10.

Refer Intel MAX 10 FPGA Configuration User Guide: https://www.intel.com/content/www/us/en/programmable/documentation/sss1393988509894.html

Regards

[Tom_B]

Thanks! That worked. I should have figured out that  fiftyfivenm_jtag would go with the Max 10 device, since it uses 55nm silicon.