P87C51RB2 PHILIPS [NXP Semiconductors], P87C51RB2 Datasheet - Page 8

• Manufacturer Part Number: P87C51RB2
• Description: 80C51 8-bit microcontroller family
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
NOTE:
To avoid “latch-up” effect at power-on, the voltage on any pin (other than V
2003 Jan 24
PSEN
EA/V
XTAL1
XTAL2
MNEMONIC
MNEMONIC
80C51 8-bit microcontroller family
with 512B/1KB RAM, low voltage (2.7 to 5.5 V), low power, high
speed (30/33 MHz)
PP
PDIP
29
31
19
18
PIN NUMBER
PLCC
32
35
21
20
LQFP
26
29
15
14
8KB/16KB/32KB/64KB OTP
TYPE
TYPE
O
O
I
I
Program Store Enable: The read strobe to external program memory. When
executing code from the external program memory, PSEN is activated twice each
machine cycle, except that two PSEN activations are skipped during each access
to external data memory. PSEN is not activated during fetches from internal
program memory.
External Access Enable/Programming Supply Voltage: EA must be externally
held low to enable the device to fetch code from external program memory
locations. If EA is held high, the device executes from internal program memory.
The value on the EA pin is latched when RST is released and any subsequent
changes have no effect. This pin also receives the programming supply voltage
(V
Crystal 1: Input to the inverting oscillator amplifier and input to the internal clock
generator circuits.
Crystal 2: Output from the inverting oscillator amplifier.
PP
) during programming.
8
PP
) must not be higher than V
NAME AND FUNCTION
NAME AND FUNCTION
P87C51RA2/RB2/RC2/RD2
CC
+ 0.5 V or less than V
SS
Product data
– 0.5 V.