Read MWIR Register
WIR Mode Enabled When
Latched EMU0 == 0
Latched EMU1 == 1
WIR Mode ?
yes
no
Master Subsystem Reset Released
(go to M-bootROM)
Continue With
M-bootROM Procedure
Read CWIR Register
WIR Mode Enabled When
Latched EMU0 == 0
Latched EMU1 == 1
WIR Mode ?
Control Subsystem Reset Released
(go to C-BootROM)
Continue With
C28 Boot Procedure
WIR Mode ?
Read MWIR Register
yes
no
Read CWIR Register
Release Control subsystem out of reset
yes
no
WIR Mode ?
no
yes
WIR Mode
95
SPRUHE8E – October 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
System Control and Interrupts
Figure 1-2. Master and Control Subsystem WIR Mode Flow
1.4.2 Exiting WIR Mode
As explained earlier, after the master subsystem and/or control subsystem enter WIR mode, they stay in
this mode as long as the EMU0 and EMU1 bits in the respective WIR register are set to match the
WIR_MODE_YES value. If they do not match the WIR_MODE_YES value, then the boot ROM continues
its execution by exiting the WIR mode. Although both the boot ROMs in the master subsystem and control
subsystem continue to read the WIR mode register, they do not force the EMU0 and EMU1 bits to re-latch
the EMU0 and EMU1 pin status by setting the sample bits. So in order to force re-latching of the EMU0
and EMU1 bits of WIR mode registers, the user has to give an XRS reset or has to set the re-sample bit
from the debugger.
Below are different options for bringing the device out of WIR mode after it enters the mode.
•
Set EMU0 and EMU1 pins on the device to a value other than the WIR_MODE_YES value as shown
in
and give an XRS reset to the device. Refer to the device-specific data manual for more
details on the pin locations.
•
EMU0 and EMU1 bits in MWIR and CWIR registers are R/W type bits and are reset to the actual state
of EMU0 and EMU1 pins on XRS reset or whenever the sample bit is set in the respective WIR
registers to re-sample these pins. The user can then directly write a value other than the
WIR_MODE_YES value (refer to
) to these bits, and not set the sample bit. Therefore, when