GOAL: I'm trying to get past a few hurdles so I can communicate with the ARM7TDMI Core using the DCC (Debug Communications Channel) registers via JTAG.
PROCESS:
1. Currently I've determined that you must select the TAP associated with the core and bypass the ICEPick. I've successfully performed this based on the information provided here http://processors.wiki.ti.com/index.php/ICEPICK
2. Once the Correct TAP is selected I can now communicate with the ARM Core, however, there are several scan chains (Sub scan chains, if you will) for the ARM Core as well. I believe that the scan chain I need to use in order to communicate with the DCC is the Scan Chain 2, "EmbeddedICE-RT Logic Programming".
3. I've performed what I believe, based on the ARM7TDMI Reference Manual, to be the process for selecting and activating Scan Chain 2
- Select Scan Chain 2
- Place Scan Chain 2 into "INTEST" mode to allow communication to and from the core.
PROBLEMS:
1. When I perform the final step "INTEST" I get the ERROR LED on my demo board... unfortunately I cannot tell what the specific error is.
2. The Section in the ARMTDMI Manual for the DCC describes 3 32-bit registers, yet the Registers available for the EmbeddedICE-RT scan chain show 2 registers one of 6-bits and one of 32-bits.
Anybody with insight on how to access the core for Memory reads/writes in real-time would be much appreciated.
