Table A3-1 Valid reset combinations (continued)
Reset combination
Signals
Value Description
MBIST reset
nCPUPORESET[CN:0]
nCORERESET[CN:0]
nPRESETDBG
nL2RESET
nMBISTRESET
all = 1
all = 1
1
1
0
All logic is held in reset.
Normal state
nCPUPORESET[CN:0]
nCORERESET[CN:0]
nPRESETDBG
nL2RESET
nMBISTRESET
all = 1
all = 1
1
1
1
No logic is held in reset.
Warm reset
The following figure shows the Warm reset sequence for the Cortex
‑
A35 processor.
CLK
nCPUPORESET[N:0]
nPRESETDBG
nCORERESET[N:0]
nL2RESET
3
CLK
cycles minimum
Figure A3-1 Warm reset timing
Individual core Warm reset initializes all logic in a single core apart from its Debug, ETM, breakpoint,
and watchpoint logic. Breakpoints and watchpoints for that core are retained. You must apply the correct
sequence before applying Warm reset to that core.
For individual processor Warm reset:
• You must apply steps 1 to 6 in the core powerdown sequence, see
A4.6 Powering down an individual
, and wait until
STANDBYWFI
is asserted, indicating that the core is idle,
before asserting
nCORERESET
for that core.
•
nCORERESET
for that core must assert for at least 3 CLK cycles.
•
nL2RESET
must not assert while any individual core is active.
•
nPRESETDBG
must not assert while any individual core is actively being debugged in normal
operating mode.
Note
If core dynamic retention using the CPU Q-channel interface is used, the core must be in quiescent state
with
STANDBYWFI
asserted and
CPUQREQn
,
CPUQACCEPTn
, and
CPUQACCEPT
must be
LOW before
nCORERESET
is applied.
A3 Clocks, Resets, and Input Synchronization
A3.3 Resets
100236_0100_00_en
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A3-54
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