TAP, Boundary Scan, and OCE
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
25-11
25.1.6 DEBUG_REQUEST and ENABLE_ONCE Commands
After completing the CHOOSE_ONCE instruction, you can execute DEBUG_REQUEST and
ENABLE_ONCE instructions. More than one such instruction can execute, and other
instructions can be placed between them, as well as between them and the CHOOSE_ONCE
instruction. The OCE modules selected in the CHOOSE_ONCE instruction remain selected until
the next CHOOSE_ONCE instruction. The DEBUG_REQUEST or ENABLE_ONCE instruction
is shifted in during the
SHIFT
-
IR
state, as are all JTAG instructions.
25.1.7 RD_STATUS Command
In the OCE, the status bits are no longer shifted out when shifting in any JTAG instruction.
Instead, there is a special instruction which will return the status of selected core(s). Figure 25-6
shows an example of CORE_CMD and RD_STATUS instructions.
Figure 25-6. CORE_CMD and RD_STATUS Flow
Wait for core to enter debug or
Execute a DEBUG_REQUEST instruction.
Issue RD_STATUS JTAG command
Execute choose_EONCE instruction and enable_ONCE in JTAG
.
Continue as required.
Shift out RD_STATUS register
Issue ENABLE_ONCE JTAG command
Execute the CORE_CMD
Is the
system idle?
Is the
SYS IDLE
needed?
No
Yes
SYS IDLE
required?
Yes
No
need
another
CORE_CMD?
No
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...