
80C196KB USER’S GUIDE
For the 87C196KB, the ROM dump mode is entered
like the other programming modes described in Section
16.1 with PMODE equal to 6H. For the 83C196KB,
the ROM Dump Mode is entered by placing EA at a
TTL high, holding ALE low and holding INST and
RD high on the rising edge of RESET. The device first
verifies the security key. If the security keys do not
match, the device puts itself into an endless loop of
internal execution. If the keys match, the device dumps
internal locations 2000H-3FFFH to external locations
4000H – 5FFFH.
16.9 Algorithms
The Modified Quick-Pulse Algorithm
The Modified Quick-Pulse Algorithm must be used to
guarantee programming over the life of the EPROM in
Run-time and Slave Programming Modes.
The Modified Quick-Pulse Algorithm calls for each
EPROM location to receive 25 separate 100 uS (
g
5
m
s) programming cycles. Verification is done after the
25th pulse. If the location verifies, the next location is
programmed. If the location fails to verify, the location
fails the programming sequence.
Once all locations are programmed and verified, the
entire EPROM is again verified.
Programming of 87C196KB EPROMs is done with
V
PP
e
12.75V
g
0.25V and V
CC
e
5.0V
g
0.5V.
Signature Word
The 87C196KB contains a signature word at location
2070H. The word can be accessed in the Slave Mode by
executing a Word Dump Command. The programming
voltages are determined by reading the test ROM at
locations 2072H and 2073H. The voltages are calculat-
ed by using the following equation.
Voltage
e
20/256
*
(test ROM data)
The values for the signature word and voltage levels are
shown in Figure 16-10.
Description
Location
Value
Signature Word
2070H
897CH
Programming V
CC
2072H
040H
(5.0V)
Programming V
PP
2073H
0A3H
(12.75V)
Figure 16-10. Signature Word and Voltage Levels
Erasing the 87C196KB
After each erasure, all bits of the 87C196KB are logical
1s. Data is introduced by selectively programming 0s.
The only way to change a 0 to a 1 is by exposure to
ultraviolet light.
Erasing begins upon exposure to light with wavelengths
shorter than approximately 4000 Angstroms. It should
be noted that sunlight and certain types of fluorescent
lamps have wavelengths in the 3000-4000 Angstrom
range. Constant exposure to room level fluorescent
lighting could erase an 87C196KB in about 3 years. It
would take about 1 week in direct sunlight to erase an
87C196KB.
Opaque labels should always be placed over the win-
dow to prevent unintentional erasure. In the Power-
down Mode, the part will draw more current than nor-
mal if the EPROM window is exposed to light.
The
recommended
erasure
procedure
for
the
87C196KB is exposure to ultraviolet light which has a
wavelength of 2537 Angstroms. The integrated dose
(UV intensity
*
exposure time) should be a minimum of
15 Wsec/cm
2
. The total time for erasure is about 15 to
20 minutes at this level of exposure. The 87C196KB
should be placed within 1 inch of the lamp during expo-
sure. The maximum integrated dose an 87C196KB can
be exposed to without damage is 7258 Wsec/cm
2
(1
week
@
12000 uW/cm
2
). Exposure to UV light greater
than this can cause permanent damage.
94
数控原理与维修
http://www.agreenleaf.cn
Содержание 80C196KB Series
Страница 1: ...November 1990 80C196KB User s Guide Order Number 270651 003 http www agreenleaf cn...
Страница 59: ...80C196KB USER S GUIDE Figure 11 7 Ideal A D Characteristic 270651 37 55 http www agreenleaf cn...
Страница 60: ...80C196KB USER S GUIDE Figure 11 8 Actual and Ideal Characteristics 270651 38 56 http www agreenleaf cn...
Страница 61: ...80C196KB USER S GUIDE Figure 11 9 Terminal Based Characteristic 270651 39 57 http www agreenleaf cn...
Страница 70: ...80C196KB USER S GUIDE Figure 13 5 Reset Sequence 80C196KB Reset Sequence 270651 45 66 http www agreenleaf cn...
Страница 83: ...80C196KB USER S GUIDE 270651 80 Figure 15 14 AC Timing Diagrams 79 http www agreenleaf cn...
Страница 84: ...80C196KB USER S GUIDE 270651 81 270651 84 Figure 15 14 AC Timing Diagrams Continued 80 http www agreenleaf cn...