Datasheet

DS87C520/DS83C520 EPROM/ROM High-Speed Microcontrollers
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EXPLANATION OF AC SYMBOLS
In an effort to remain compatible with the original 8051 family, the DS87C520 and DS83C520 specify
the same parameters as such devices, using the same symbols. For completeness, the following is an
explanation of the symbols.
t Time
A Address
C Clock
D Input data
H Logic level high
L Logic level low
I Instruction
P PSEN
Q Output data
R RD signal
V Valid
W WR signal
X No longer a valid logic
level
Z Tri-State
POWER-CYCLE TIMING CHARACTERISTICS
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Cycle Startup Time t
CSU
1.8 ms 1
Power-On Reset Delay t
POR
65,536 t
CLCL
2
Note 1: Startup time for crystals varies with load capacitance and manufacturer. Time shown is for an 11.0592MHz crystal
manufactured by Fox.
Note 2: Reset delay is a synchronous counter of crystal oscillations after crystal startup. Counting begins when the level
on the XTAL1 pin meets the V
IH2
criteria. At 33MHz, this time is 1.99ms.
EPROM PROGRAMMING AND VERIFICATION
(V
CC
= 4.5V to 5.5V, T
A
= +21C to +27°C.)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Programming Voltage V
PP
12.5 13.0 V 1
Programming Supply Current I
PP
50 mA
Oscillator Frequency 1/t
CLCL
4 6 MHz
Address Setup to
PROG
Low
t
AVGL
48t
CLCL
Address Hold after PROG
t
GHAX
48 t
CLCL
Data Setup to PROG Low
t
DVGL
48 t
CLCL
Data Hold after PROG
t
GHDX
48 t
CLCL
Enable High to V
PP
t
EHSH
48 t
CLCL
V
PP
Setup to PROG Low
t
SHGL
10 μs
V
PP
Hold after PROG
t
SHGL
10 μs
PROG Width
t
GLGH
90 110 μs
Address to Data Valid t
AVQV
48 t
CLCL
Enable Low to Data Valid t
ELQV
48 t
CLCL
Data Float after Enable t
EHQZ
0 48 t
CLCL
PROG High to PROG Low
t
GHGL
10 μs
Note 1:
All voltages are referenced to ground.