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10.3 Types of Reset
10.3.1 Power-On Reset (POR)
10.3.2 Warm Reset
Types of Reset
POR totally resets the chip, including all modules, memories, and emulation circuitry.
The following steps describe the POR sequence:
1. Apply power and clocks to the chip and drive TRSTN and RESETN low to initiate POR.
2. Drive RESETN high after a required minimum number of MXI clock cycles.
3. Hardware latches the device configuration pins on the rising edge of RESETN. The device
configuration pins allow you to set several options at reset. See
for more information.
4. Hardware resets all of the modules, including memory and emulation circuitry.
5. POR finishes, all modules are now in their default configurations, and hardware begins the boot
process.
See the DM355 Data Manual (
SPRS348
) for power sequencing and reset timing requirements.
Warm reset is like POR, except the ARM emulation circuitry is not reset. Warm reset allows an ARM
emulator to initiate chip reset using TRSTN and RESETN while remaining active during and after the reset
sequence.
The following steps describe the warm reset sequence:
1. Emulator drives TRSTN high and RESETN low to initiate warm reset.
2. Emulator drives RESETN high after a required minimum number of MXI clock cycles.
3. Hardware latches the device configuration pins on the rising edge of RESETN. The device
configuration pins allow you to set several options at reset. See
below for more
information.
4. Hardware resets all of the modules including memories, but not ARM emulation circuitry.
5. Warm reset finishes, all modules except ARM emulation are in their default configurations, and
hardware begins the boot process.
See the DM355 Data Manual (
SPRS348
) for reset timing requirements.
Reset
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SPRUFB3 – September 2007