Datasheet

Table Of Contents
Rev. J | Page 18 of 60 | July 2013
ADSP-21362/ADSP-21363/ADSP-21364/ADSP-21365/ADSP-21366
Power-Up Sequencing
The timing requirements for processor startup are given in
Table 10. Note that during power-up, when the V
DDINT
power
supply comes up after V
DDEXT
, a leakage current of the order of
three-state leakage current pull-up, pull-down, may be observed
on any pin, even if that is an input only (for example the RESET
pin) until the V
DDINT
rail has powered up.
Table 10. Power-Up Sequencing Timing Requirements (Processor Startup)
Parameter Min Max Unit
Timing Requirements
t
RSTVDD
RESET Low Before V
DDINT
/V
DDEXT
On 0 ns
t
IVDDEVDD
V
DDINT
On Before V
DDEXT
–50 +200 ms
t
CLKVDD
1
CLKIN Valid After V
DDINT
/V
DDEXT
Valid 0 200 ms
t
CLKRST
CLKIN Valid Before RESET Deasserted 10
2
μs
t
PLLRST
PLL Control Setup Before RESET Deasserted 20 μs
Switching Characteristic
t
CORERST
Core Reset Deasserted After RESET Deasserted 4096t
CK
+ 2 t
CCLK
3,
4
1
Valid V
DDINT
/V
DDEXT
assumes that the supplies are fully ramped to their 1.2 V rails and 3.3 V rails. Voltage ramp rates can vary from microseconds to hundreds of milliseconds,
depending on the design of the power supply subsystem.
2
Assumes a stable CLKIN signal, after meeting worst-case start-up timing of crystal oscillators. Refer to your crystal oscillator manufacturer’s data sheet for start-up time.
Assume a 25 ms maximum oscillator start-up time if using the XTAL pin and internal oscillator circuit in conjunction with an external crystal.
3
Applies after the power-up sequence is complete. Subsequent resets require a minimum of 4 CLKIN cycles for RESET to be held low to properly initialize and propagate
default states at all I/O pins.
4
The 4096 cycle count depends on t
SRST
specification in Table 12. If setup time is not met, 1 additional CLKIN cycle can be added to the core reset time, resulting in 4097 cycles
maximum.
Figure 6. Power-Up Sequencing
t
RSTVDD
t
CLKVDD
t
CLKRST
t
CORERST
t
PLLRST
V
DDEXT
V
DDINT
CLKIN
CLK_CFG1–0
RESET
RESETOUT
t
IVDDEVDD