N87C511SF76 Intel, N87C511SF76 Datasheet - Page 5

• Manufacturer Part Number: N87C511SF76
• Description: IC MCU 8BIT 5V 16MHZ OTP 44PLCC
• Manufacturer: Intel
• Series: 87Cr

Specifications of N87C511SF76

• Rohs Status: RoHS non-compliant
• Core Processor: MCS 51
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SIO
• Number Of I /o: 32
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• Eeprom Size: -
• Data Converters: -
• Peripherals: -
• Other names: 810977

In normal operation ALE is emitted at a constant
rate of 1/6 the oscillator frequency, and may be
used for external timing or clocking purposes. Note,
however, that one ALE pulse is skipped during each
access to external Data Memory.
PSEN: Program Store Enable is the Read strobe to
External Program Memory. When the 87C51/BH is
executing from Internal Program Memory, PSEN is
inactive (high). When the device is executing code
from External Program Memory, PSEN is activated
twice each machine cycle, except that two PSEN
activations are skipped during each access to Exter-
nal Data Memory.
EA/V
strapped to V
fetch code from External Program Memory locations
starting at 0000H up to FFFFH. Note, however, that
if either of the Lock Bits is programmed, the logic
level at EA is internally latched during reset.
EA must be strapped to V
execution.
This pin also receives the programming supply volt-
age (V
XTAL1 : Input to the inverting oscillator amplifier.
XTAL2 : Output from the inverting oscillator amplifi-
er.
PP
Figure 3. Using the On-Chip Oscillator
PP
: External Access enable. EA must be
) during EPROM programming.
SS
in order to enable the 87C51/BH to
CC
for internal program
272335 ±5
OSCILLATOR CHARACTERISTICS
XTAL1 and XTAL2 are the input and output, respec-
tively, of an inverting amplifier which can be config-
ured for use as an on-chip oscillator, as shown in
Figure 3.
To drive the device from an external clock source,
XTAL1 should be driven, while XTAL2 is left uncon-
nected, as shown in Figure 4. There are no require-
ments on the duty cycle of the external clock signal,
since the input to the internal clocking circuitry is
through a divide-by-two flip-flop, but minimum and
maximum high and low times specified on the data
sheet must be observed.
An external oscillator may encounter as much as a
100 pF load at XTAL1 when it starts up. This is due
to interaction between the amplifier and its feedback
capacitance. Once the external signal meets the V
and V
ceed 20 pF.
IH
specifications the capacitance will not ex-
Figure 4. External Clock Drive
87C51/80C51BH/80C31BH
272335 ±6
IL
5