User manual

10.3.3 Maximum (Max) Reset
10.3.4 System Reset
10.3.5 Module Reset
10.3.6 DSP Local Reset
Types of Reset www.ti.com
A Maximum (Max) reset is initiated by the emulator or the watchdog timer (Timer2). The effects are the
same as a Warm reset, except the device boot and configuration pins are not relatched. The emulator
initiates a Max reset via the ICEPICK module. This ICEPICK-initiated reset is nonmaskable. When the
watchdog timer counter reaches zero, this also initiates a Max reset to recover from a runaway condition.
For debug, Max reset allows an emulator to initiate chip reset using an emulation command, while
remaining active during and after the reset sequence. To invoke the Max reset via the ICEPICK module,
you can perform the following from the Code Composer Studio™ IDE menu: Debug → Advanced
Resets → System Reset.
The following steps describe the Max reset sequence:
1. To initiate Max reset, the watchdog timer expires (indicating a runaway condition), or the emulator
initiates a Max reset command via the ICEPICK module.
2. Hardware resets all of the modules including memories, but not the emulation circuitry. The device
boot and configuration pins are not relatched.
3. Warm reset finishes, all of the modules except emulation logic are in their default configurations, and
hardware begins the boot process.
Note: Max reset may be blocked by an emulator command. This allows an emulator to block a
watchdog timer-initiated Max reset for debug purposes.
See the TMS320DM646x DMSoC 64-Bit Timer User's Guide (SPRUER5 ) for information on the watchdog
timer.
The emulator initiates System reset via special DSP emulation or ICECrusher. System reset is considered
a soft reset (memory contents are maintained, clock logic and power control logic are not affected). None
of the following modules are reset: DDR2 Memory Controller, PLL Controller (PLLC), Power and Sleep
Controller (PSC), and emulation circuitry.
The following steps describe the System reset sequence:
1. The emulator initiates System reset.
2. The proper modules are reset.
3. The System reset finishes, the proper modules are reset, and the CPU is out of reset.
Module reset allows the software to independently reset a module. Module reset can be used to return a
module to its default state (that is, its state as seen after POR, Warm reset, and Max reset). Module reset
is intended as a debug tool; rather than for general use, because if care is not taken arbitrarily setting a
module can result in the switch fabric locking up.
The procedures for asserting and deasserting module reset are fully described in Chapter 6 . Furthermore,
special considerations for DSP module reset are described in Chapter 12 .
You can use DSP local reset to reset the DSP CPU. When the DSP local reset is asserted, the DSP
internal memories (L1P, L1D, and L2) are still accessible. Unlike Module reset, local reset only resets the
DSP CPU. The ARM uses local reset to reset the DSP during the DSP boot process.
Note: Module reset supersedes local reset, so you can execute a module reset when local reset is
asserted or deasserted.
The procedures for asserting and deasserting DSP local reset are fully described in the Chapter 12 and
Chapter 6 .
Reset114 SPRUEP9A – May 2008
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