ARM JTAG and DFT JTAG as well as SWD and 1149.7

Make it to the Right and Larger Audience

Blog/Press Release

ARM JTAG and DFT JTAG as well as SWD and 1149.7

Inspired by an interesting slides about Jtag IEEE 1149.7 from Stephen Lau of TI (included in below), here we briefly talk about arm Jtag and DFT Jtag, as well as latest arm SWD and 1149.7. They are commonly seen in a typical ASIC design.

Today’s ASIC normally has an arm processor embedded in it. Therefore arm Jtag is needed to connect to external ICE debugger for firmware development, debug, and test. The following diagram comes from Arm Dap-lite specification.

 

ajtag_1

 

Debug Access Port (DAP) contains the following components:
serial wire Jtag debug port (SWJ-DP)
APB access port (APB-AP)
APB multiplexor (APB-Mux)
ROM table.
On one side, SWJ-DP interfaces to Jtag pins directly. On the other side, debug APB is connected to arm processor debug APB port, which is connected to an APB slave resided inside arm processor core. APB-AP basically converts Jtag control into APB control and the APB master inside APB-AP can drive debug APB port and therefore accesses arm processor core. Debug APB can also be driven by “system access” APB. This one is optional and lots of times you can connect it to an APB master on your AXI/AHB bus. (Note for details, please check DAP-lite specification directly: http://infocenter.arm.com/help/topic/com.arm.doc.ddi0316d/DDI0316D_dap_lite_trm.pdf )

 

ajtag_2

The following is author subscription content.
To gain access you can subscribe to this author's posts at Subscription of SD-RTL-DGN Posts. Subscription is valid for three months.
Highlights: 675 words, 1 images
 
Profile Photo
We are a small team of ASIC and FPGA design engineers with combined >40 years of experience. We successfully led several chips through the whole design to TO process. Familiar with Xilinx FPGA, we designed complicated system of using multiple FPGAs to verify complicated ASIC and also for the final products. We are interested in working as independent contractor for your projects. Feel free to contact us.
Groups:

0 Comments

Contact Us

Thanks for helping us better serve the community. You can make a suggestion, report a bug, a misconduct, or any other issue. We'll get back to you using your private message ASAP.

Sending

©2019  ValPont.com

Forgot your details?