Public Version
ICEPick Module
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27.2.5.2 Adding a TAP in the Debug Chain
The following sequence adds a new TAP in the debug chain:
1. Select IR scan.
2. Send the ROUTER instruction in IR scan (000010).
3. Select DR scan.
4. Send the following value in DR scan (see
) to enable power and clock for the TAP:
•
WRITE (bit 32) = 1
•
BLOCK (bit field [31:28]) = 0x2; bloc 2 is Debug TAP Linking Control.
•
REGISTER (bit field [27:24]) = TAP number, select the TAP to be added to the chain; see
for more information.
•
FORCEACTIVE (bit 3) = 1, enable the TAP power and clock.
•
FORCEPOWER (bit 6) = 1, force the TAP power to ON state regardless of whether the TAP is
selected or not.
•
INHIBITSLEEP (bit 20) = 1, force the TAP clock to be active.
5. Read back the value in next DR scan:
•
WRITE (bit 32) = 0
•
BLOCK (bit field [31:28]) = 0x2; block 2 is Debug TAP Linking Control.
•
REGISTER (bit field [27:24]) = TAP number , select the TAP to be added to the chain; see
for more information.
6. Check if the FORCEACTIVE, FORCEPOWER, and INHIBITSLEEP bits are set to 1.
7. Send the following value in DR scan (see
) to enable debug mode:
•
WRITE (bit 32) = 1
•
BLOCK (bit field [31:28]) = 0x2; block 2 is Debug TAP Linking Control.
•
REGISTER (bit field [27:24]) = TAP number , select the TAP to be added to the chain; see
for more information.
•
DEBUGENABLE (bit 13) = 1; enable the TAP debug.
•
DEBUGMODE (bit field [12:11]) = MODE; see
for available debug modes.
8. Read back the value in next DR scan:
•
WRITE (bit 32) = 0
•
BLOCK (bit field [31:28]) = 0x2; block 2 is Debug TAP Linking Control.
•
REGISTER (bit field [27:24]) = TAP number , select the TAP to be added to the chain; see
for more information.
9. Check if DEBUGENABLE and DEBUGMODE bit are well set.
10. Send the following value in DR scan (see
) to add the TAP in the chain:
•
WRITE (bit 32) = 1
•
BLOCK (bit field [31:28]) = 0x2; block 2 is Debug TAP Linking Control.
•
REGISTER (bit field [27:24]) = TAP number , select the TAP to be added to the chain; see
for more information.
•
SELECTTAP (bit 8) = 1; add the TAP in the chain.
11. Go in Run Test Idle (RTI) so the change takes effect and the TAP is added to the chain (a wait may
be needed).
When the TAP is added to the chain, DR and IR are longer (ICEPick new TAP).
To write in IR for the new TAP, write BYPASS in ICEPick IR so the next DR is not taken into account and
is only 1 bit for ICEPick.
3606
Debug and Emulation
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated
