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6.4 Reset
TMS320DM6443
Digital Media System-on-Chip
SPRS282E–DECEMBER 2005–REVISED MARCH 2007
DM6443 supports various types of resets. Power-on-reset (POR), warm reset, max reset, system reset,
C64x+ local reset, and module reset are summarized in
Table 6-7
.
Table 6-7. DM6443 Resets
Type
Power-on-reset (POR)
Initiator
RESET pin active low while TRST is low.
Description
Global chip reset (Cold reset). Activates the POR signal
on chip, which is used to reset test and emulation logic.
Resets everything except for test and emulation logic.
ARM emulator stays alive during warm reset, but the
C64x+ emulator does not.
Same as Warm reset, except for initiators.
MMR controls the C64x+ reset input. This is used for
control of C64x+ reset by the ARM. The C64x+ Slave
DMA port is still alive when in local reset.
Warm reset
RESET pin active low while TRST is high.
Maximum reset
C64x+ Local reset
Emulator, WD Timer
Software (register bit)
Power-on-reset (POR) is the global chip reset and it affects test, emulation, and other circuitry. It is
invoked by driving the RESET pin active low while TRST is held low. A POR is required to place DM6443
into a known good initial state. POR can be asserted prior to ramping the core and I/O voltages or after
the core and I/O voltages have reached their proper operating conditions. As a best practice, RESET
should be asserted (held low) during power-up. Prior to deasserting RESET (low-to-high transition), the
core and I/O voltages should be at their proper operating conditions and if an external 27 MHz oscillator is
used on the MXI/CLKIN pin, the external clock should also be running at the correct frequency.
Warm reset is activated by driving the RESET pin active low, while TRST is inactive high. This does not
reset test or ARM emulation logic. An ARM emulator session will stay alive during warm reset, but a
C64x+ emulator session will not.
Maximum reset is initiated by the emulator or the watchdog timer and the reset effects are the same as a
warm reset. The emulator initiates a maximum reset via the ICEPICK module. When the watchdog timer
counter reaches zero, this will initiate a maximum reset to recover from a runaway condition. Both of the
maximum reset initiators can be masked by the ARM emulator.
System reset is initiated by the emulator and is a soft reset. Memory contents are maintained. Test,
emulation, clock, and power control logic are unaffected. The emulator initiates a system reset via the
C64x+ emulation logic, or through ICECRUSHER. Both of these reset initiators are non-maskable resets.
The C64x+ DSP has an internal reset input that allows a host to control it. This reset is configured through
a MMR bit (MDCTL[39].LRSTz) in the PSC module. When in C64x+ local reset, the slave DMA port on
C64x+ will remain active and the internal memory will be accessible.
For details on reset control/status registers, see the
TMS320DM644x DMSoC ARM Subsystem Reference
Guide
(literature number
SPRUE14
)
For information on peripheral selection at the rising edge of RESET, see the
Device Configuration
section
of this data manual.
Peripheral and Electrical Specifications
98
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