MSC8144 Freescale Semiconductor, MSC8144 Datasheet - Page 35

• Manufacturer Part Number: MSC8144
• Description: Quad Core Digital Signal Processor
• Manufacturer: Freescale Semiconductor

2.7
The following sections include illustrations and tables of clock diagrams, signals, and parallel I/O outputs and inputs.
2.7.1
Starting the device requires coordination among several input sequences including clocking, reset, and power. Section 2.7.2
describes the clocking characteristics. Section 2.7.3 describes the reset and power-up characteristics. You must use the
following guidelines when starting up an MSC8144 device:
Note:
Figure 7 shows a sequence in which
Freescale Semiconductor
Output low voltage, I
Notes:
•
•
•
PORESET and TRST must be asserted externally for the duration of the power-up sequence using the V
supply. See Table 24 for timing. TRST deassertion does not have to be synchronized with PORESET deassertion.
During functional operation when JTAG is not used, TRST can be asserted and remain asserted after the power ramp.
For applications that use M3 memory, M3_RESET should replicate the PORESET sequence timing, but using the
V
CLKIN should start toggling at least 32 cycles before the PORESET deassertion to guarantee correct device operation
(see Figure 7). 32 cycles should be accounted only after V
CLKIN and PCI_CLK_IN should either be stable low during the power-up of V
power-up or should swing within V
during power-up.
1.
2.
DDM3IO
AC Timings
See Figure 6 for undershoot and overshoot voltages.
Not tested. Guaranteed by design.
Start-Up Timing
V
V
OL
IL
(2.5 V) supply. See Section 3.1.1, Power-on Sequence for additional design information.
IH
= 3.2 mA
Table 19. GPIO and CLKIN DC Electrical Characteristics (continued)
Characteristic
MSC8144 Quad Core Digital Signal Processor Data Sheet, Rev. 1
V
Figure 6. Overshoot/Undershoot Voltage for V
GND – 0.3 V
GND – 0.7 V
V
DDIO
DDIO
V
+ 17%
V
GND
+ 5%
DDIO
DDIO
is raised after
DDIO
range during V
Must not exceed 10% of clock period
V
DD
and
DDIO
CLKIN
DDIO
Symbol
power-up., so their amplitude grows as V
V
OL
reaches its nominal value.
begins to toggle with the raise of
IH
Min
DDIO
—
and V
supply and start their swings after
IL
Electrical Characteristics
Max
0.4
V
DDIO
DDIO
DDIO
supply.
Unit
grows
V
(3.3 V)
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