ADSP-21MOD870_15 Datasheet, PDF (16/32 Pages) Analog Devices – Internet Gateway Processor

ADSP-21mod870
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +4.6 V
Input Voltage . . . . . . . . . . . . . . . . . . . . –0.5 V to V_DD + 0.5 V
Output Voltage Swing . . . . . . . . . . . . . –0.5 V to V_DD + 0.5 V
Operating Temperature Range (Ambient) . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Lead Temperature (5 sec) LQFP . . . . . . . . . . . . . . . . +280°C
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. These are stress ratings only; functional operation of
the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
TIMING PARAMETERS
GENERAL NOTES
Use the exact timing information given. Do not attempt to
derive parameters from the addition or subtraction of others.
While addition or subtraction would yield meaningful results for
an individual device, the values given in this data sheet reflect
statistical variations and worst cases. Consequently, you cannot
meaningfully add up parameters to derive longer times.
TIMING NOTES
Switching characteristics specify how the processor changes its
signals. You have no control over this timing—circuitry external
to the processor must be designed for compatibility with these
signal characteristics. Switching characteristics tell you what the
processor will do in a given circumstance. You can also use
switching characteristics to ensure that any timing requirement
of a device connected to the processor (such as memory) is
satisfied.
Timing requirements apply to signals that are controlled by
circuitry external to the processor, such as the data input for a
read operation. Timing requirements guarantee that the proces-
sor operates correctly with other devices.
MEMORY TIMING SPECIFICATIONS
The table below shows common memory device specifications
and the corresponding ADSP-21mod870 timing parameter.
Memory
Device
Specification
Address Setup to
Write Start
Address Setup to
Write End
Address Hold Time
Data Setup Time
Data Hold Time
OE to Data Valid
Address Access Time
ADSP-
21mod870
Timing
Parameter
t_ASW
t_AW
t_WRA
t_DW
t_DH
t_RDD
t_AA
Timing
Parameter
Definition
A0–A13, xMS Setup
before WR Low
A0–A13, xMS Setup
before WR Deasserted
A0–A13, xMS Hold
before WR Low
Data Setup before WR
High
Data Hold after WR High
RD Low to Data Valid
A0–A13, xMS to Data
Valid
Note: xMS = PMS, DMS, BMS, CMS, IOMS.
FREQUENCY DEPENDENCY FOR TIMING
SPECIFICATIONS
t_CK is defined as 0.5 t_CKI. The ADSP-21mod870 uses an input
clock with a frequency equal to half the instruction rate: a
26 MHz input clock (which is equivalent to 38 ns) yields a 19 ns
processor cycle (equivalent to 52 MHz). t_CK values within the
range of 0.5 t_CKI period should be substituted for all relevant tim-
ing parameters to obtain the specification value.
Example: t_CKH = 0.5 t_CK – 7 ns = 0.5 (19 ns) – 7 ns = 2.5 ns
ENVIRONMENTAL CONDITIONS
Ambient Temperature Rating:
T_AMB =
T_CASE =
PD =
θ_CA =
θ_JA
=
θ_JC
=
T_CASE – (PD × θ_CA)
Case Temperature in °C
Power Dissipation in W
Thermal Resistance (Case-to-Ambient)
Thermal Resistance (Junction-to-Ambient)
Thermal Resistance (Junction-to-Case)
Package
LQFP
␪_JA
50°C/W
␪_JC
2°C/W
␪_CA
48°C/W
ESD SENSITIVITY
The ADSP-21mod870 is an ESD (electrostatic discharge) sensitive device. Electrostatic charges
readily accumulate on the human body and equipment and can discharge without detection.
Permanent damage may occur to devices subjected to high energy electrostatic discharges.
The ADSP-21mod870 features proprietary ESD protection circuitry to dissipate high energy
discharges (Human Body Model) per method 3015 of MIL-STD-883. Proper ESD precautions are
recommended to avoid performance degradation or loss of functionality. Unused devices must be
stored in conductive foam or shunts, and the foam should be discharged to the destination before
devices are removed.
WARNING!
ESD SENSITIVE DEVICE
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