Freescale SemiconDdevuiccetUoserr,GIunidce.— 9S12E128DGV1/D V01.04
B.4 Reset, Oscillator and PLL
This section summarizes the electrical characteristics of the various startup scenarios for Oscillator and
Phase-Locked-Loop (PLL).
B.4.1 Startup
Table B-2 summarizes several startup characteristics explained in this section. Detailed description of the
startup behavior can be found in the Clock and Reset Generator (CRG) Block User Guide.
Table B-2 Startup Characteristics
Conditions are shown in Table A-4 unless otherwise noted
Num C
Rating
Symbol Min
1
T POR release level
2
T POR assert level
VPORR
VPORA
0.97
3
D Reset input pulse width, minimum input time
PWRSTL
2
4
D Startup from Reset
nRST
192
5
D Interrupt pulse width, IRQ edge-sensitive mode PWIRQ
20
6
D Wait recovery startup time
tWRS
7
P LVR release level
VLVRR
2.25
8
P LVR assert level
VLVRA
Typ
Max
2.07
196
14
2.55
Unit
V
V
tosc
nosc
ns
tcyc
V
V
B.4.1.1 POR
The release level VPORR and the assert level VPORA are derived from the VDD Supply. They are also valid
if the device is powered externally. After releasing the POR reset the oscillator and the clock quality check
are started. If after a time tCQOUT no valid oscillation is detected, the MCU will start using the internal self
clock. The fastest startup time possible is given by nuposc.
B.4.1.2 LVR
The release level VLVRR and the assert level VLVRA are derived from the VDD Supply. They are also valid
if the device is powered externally. After releasing the LVR reset the oscillator and the clock quality check
are started. If after a time tCQOUT no valid oscillation is detected, the MCU will start using the internal self
clock. The fastest startup time possible is given by nuposc.
B.4.1.3 SRAM Data Retention
Provided an appropriate external reset signal is applied to the MCU, preventing the CPU from executing
code when VDD5 is out of specification limits, the SRAM contents integrity is guaranteed if after the reset
the PORF bit in the CRG Flags Register has not been set.
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