N80C251SQ16 Intel, N80C251SQ16 Datasheet - Page 12

• Manufacturer Part Number: N80C251SQ16
• Description: IC MPU 8-BIT 5V 16MHZ 44-PLCC
• Manufacturer: Intel
• Series: 80Cr

Specifications of N80C251SQ16

• Rohs Status: RoHS non-compliant
• Core Processor: MCS 251
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SIO
• Peripherals: PWM, WDT
• Number Of I /o: 32
• Program Memory Type: ROMless
• Ram Size: 512 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: -
• Program Memory Size: -
• Data Converters: -
• Other names: 804459

12
8XC251SA/SB/SP/SQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
V
V
V
V
WAIT#
WCLK
WR#
XTAL1
XTAL2
†
PP
SS
SS
SS
Signal
The descriptions of A15:8/P2.7:0 and AD7:0/P0.7:0 are for the nonpage-mode chip configuration (com-
patible with 44-pin PLCC and 40-pin DIP MCS 51 microcontrollers). If the chip is configured for page-
mode operation, port 0 carries the lower address bits (A7:0), and port 2 carries the upper address bits
(A15:8) and the data (D7:0).
Name
1
2
Type
GND
GND
GND
O
O
O
I
I
I
Programming Supply Voltage. The programming supply voltage is
applied to this pin for programming the on-chip OTPROM/EPROM.
Secondary Ground. This ground is provided to reduce ground bounce
and improve power supply bypassing. Connection of this pin to ground
is recommended. However, when using the 8XC251SA/SB/SP/SQ as
a pin-for-pin replacement for the 8XC51BH, V
without loss of compatibility. (Not available on DIP)
Secondary Ground 2. This ground is provided to reduce ground
bounce and improve power supply bypassing. Connection of this pin to
ground is recommended. However, when using the 8XC251SB as a
pin-for-pin replacement for the 8XC51FX, V
without loss of compatibility. (Not available on DIP)
Real-time Wait State Input. The real-time WAIT# input is enabled by
writing a logical ‘1’ to the WCON.0 (RTWE) bit at S:A7H. During bus
cycles, the external memory system can signal ‘system ready’ to the
microcontroller in real time by controlling the WAIT# input signal on the
port 1.6 input.
Wait Clock Output. The real-time WCLK output is driven at port 1.7
(WCLK) by writing a logical ‘1’ to the WCON.1 (RTWCE) bit at S:A7H.
When enabled, the WCLK output produces a square wave signal with
a period of one-half the oscillator frequency.
Write. Write signal output to external memory.
Input to the On-chip, Inverting, Oscillator Amplifier. To use the
internal oscillator, a crystal/resonator circuit is connected to this pin. If
an external oscillator is used, its output is connected to this pin. XTAL1
is the clock source for internal timing.
Output of the On-chip, Inverting, Oscillator Amplifier. To use the
internal oscillator, a crystal/resonator circuit is connected to this pin. If
an external oscillator is used, leave XTAL2 unconnected.
Circuit Ground. Connect this pin to ground.
Table 6. Signal Descriptions (Continued)
Description
SS
2
SS
can be unconnected
1
can be unconnected
PRELIMINARY
EA#
—
—
—
P1.6/CEX3
P1.7/CEX4/
A17
P3.6
—
—
Alternate
Function