adsp-21462 Analog Devices, Inc., adsp-21462 Datasheet - Page 22

• Manufacturer Part Number: adsp-21462
• Description: Sharc Processor
• Manufacturer: Analog Devices, Inc.

ADSP-21462/ADSP-21465/ADSP-21467/ADSP-21469
Power-Up Sequencing
The timing requirements for processor startup are given in
Table
Table 14. Power Up Sequencing Timing Requirements (Processor Startup)
1
2
3
4
5
Parameter
Timing Requirements
t
t
t
t
t
t
Switching Characteristic
t
Valid V
Assumes a stable CLKIN signal, after meeting worst-case startup timing of crystal oscillators. Refer to your crystal oscillator manufacturer's datasheet for startup time. Assume
Based on CLKIN cycles.
Applies after the power-up sequence is complete. Subsequent resets require a minimum of four CLKIN cycles for RESET to be held low in order to properly initialize and
The 4096 cycle count depends on t
RSTVDD
EVDD-DDR2VDD
DDR2VDD_IVDD
CLKVDD
CLKRST
PLLRST
CORERST
of the power supply subsystem.
a 25 ms maximum oscillator startup time if using the XTAL pin and internal oscillator circuit in conjunction with an external crystal.
propagate default states at all I/O pins.
cycles maximum.
14.
DD_INT
1
assumes that the supply is fully ramped to its 1 volt rail. Voltage ramp rates can vary from microseconds to hundreds of milliseconds depending on the design
RESET
V DDEXT
V DD_DDR2
V DDINT
CLKIN
CLK_CFG 1-0
RESETOUT
RESET Low Before V
V
V
CLKIN Valid After V
CLKIN Valid Before RESET Deasserted
PLL Control Setup Before RESET Deasserted
Core Reset Deasserted After RESET Deasserted
DD_EXT
DD_DDR2
SRST
on Before V
specification in
on Before V
t
R S T V D D
t
D D R 2V D D _IVD D
DD_INT
DD_DDR2
DD_EXT
Table
DD_INT
Valid
16. If setup time is not met, one additional CLKIN cycle may be added to the core reset time, resulting in 4097
Rev. PrC | Page 22 of 62 | January 2009
or V
t
E V D D -D D R 2V D D
Figure 4. Power-Up Sequencing
DD_DDR2
t
C L K V D D
On
t
PL L R S T
t
C L K R S T
t
C O R E R S T
Min
0
TBD
TBD
0
10
20
4096 × t
Preliminary Technical Data
2
3
CK
+ 2 × t
CCLK
4, 5
Max
200
Unit
ms
ms
ms
ms
ms
ms
ms