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Z86C02/E02/L02
Low-Cost, 512-Byte ROM Microcontrollers
DS96DZ80301 (11/96)
P R E L I M I N A R Y
1-15
1
LOW NOISE VERSION
Low EMI Emission
The Z8
can be programmed to operate in a Low EMI emis-
sion mode by means of a mask ROM bit option (Z86C02)
or OTP bit option (Z86E02). Use of this feature results in:
I
All pre-driver slew rates reduced to 10 ns typical.
I
Internal SCLK/TCLK operation limited to a maximum of
4 MHz - 250 ns cycle time.
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Output drivers have resistances of 200 ohms (typical).
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The Low EMI mode is mask-programmable to be selected
by the customer at the time the ROM Code is submitted
(for Z86C02 only).
Oscillator divide-by-two circuitry eliminated.
PRECAUTION
Stack pointer register (SPL) at FFHex and general purpose register at FEHex are set to 00Hex after reset.
PIN FUNCTIONS
OTP Programming Mode
D7-D0
Data Bus. Data can be read from, or written to the
EPROM through this data bus.
V
CC
Power Supply. It is 5V during EPROM Read Mode
and 6.4V during the other modes (Program, Program Ver-
ify, etc.).
/CE
Chip Enable (active Low). This pin is active during
EPROM Read Mode, Program Mode, and Program Verify
Mode.
/OE
Output Enable (active Low). This pin drives the Data
Bus direction. When this pin is Low, the Data Bus is output.
When High, the Data Bus is input. This pin must toggle for
each data output read.
EPM
EPROM Program Mode. This pin controls the differ-
ent EPROM Program Modes by applying different
voltages.
V
PP
Program Voltage. This pin supplies the program volt-
age.
Clear
Clear (active High). This pin resets the internal ad-
dress counter at the High Level.
Clock
Address Clock. This pin is a clock input. The internal
address counter increases by one with one clock cycle.
/PGM
Program Mode (active Low). A Low level at this pin
programs the data to the EPROM through the Data Bus.
Application Precaution
The production test-mode environment may be enabled
accidentally during normal operation if
excessive noise
surges above V
CC
occur on the XTAL1 pin.
In addition, processor operation of Z8 OTP devices may be
affected by
excessive noise
surges on the V
PP
, /CE,
/EPM, /OE pins while the microcontroller is in Standard
Mode.
Recommendations for dampening voltage surges in both
test and OTP mode include the following:
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Using a clamping diode to V
CC.
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Adding a capacitor to the affected pin.