AT87C52X2-3CSUV Atmel, AT87C52X2-3CSUV Datasheet - Page 7
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AT87C52X2-3CSUV
Manufacturer Part Number
AT87C52X2-3CSUV
Description
Microcontrollers (MCU) Microcontroller
Manufacturer
Atmel
Datasheet
1.AT87C52X2-3CSUV.pdf
(55 pages)
Specifications of AT87C52X2-3CSUV
Data Bus Width
8 bit
Program Memory Type
EPROM
Program Memory Size
8 KB
Data Ram Size
256 B
Interface Type
UART
Maximum Clock Frequency
30 MHz
Number Of Programmable I/os
32
Number Of Timers
3 bit
Operating Supply Voltage
5 V
Maximum Operating Temperature
+ 70 C
Mounting Style
Through Hole
Package / Case
PDIL-40
Minimum Operating Temperature
0 C
Lead Free Status / Rohs Status
No
4184I–8051–02/08
Reset
ALE/PROG
PSEN
EA/V
XTAL1
XTAL2
Mnemonic
PP
DIL
13
14
15
16
17
30
29
31
19
18
9
Pin Number
LCC
15
16
17
18
19
10
33
32
35
21
20
VQFP
1.4
10
12
13
27
26
29
15
14
11
9
4
Type Name and Function
O (I) Address Latch Enable/Program Pulse: Output pulse for
O
O
O
O
I
I
I
I
I
I
INT1 (P3.3): External interrupt 1
T0 (P3.4): Timer 0 external input
T1 (P3.5): Timer 1 external input
WR (P3.6): External data memory write strobe
RD (P3.7): External data memory read strobe
Reset: A high on this pin for two machine cycles while the
oscillator is running, resets the device. An internal diffused
resistor to V
external capacitor to V
latching the low byte of the address during an access to
external memory. In normal operation, ALE is emitted at a
constant rate of 1/6 (1/3 in X2 mode) the oscillator frequency,
and can be used for external timing or clocking. Note that one
ALE pulse is skipped during each access to external data
memory. This pin is also the program pulse input (PROG)
during EPROM programming. ALE can be disabled by setting
SFR’s AUXR.0 bit. With this bit set, ALE will be inactive
during internal fetches.
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 0000H and
3FFFH (RB) or 7FFFH (RC), or FFFFH (RD). If EA is held
high, the device executes from internal program memory
unless the program counter contains an address greater than
3FFFH (RB) or 7FFFH (RC) EA must be held low for
ROMless devices. This pin also receives the 12.75V
programming supply voltage (V
programming. If security level 1 is programmed, EA will be
internally latched on Reset.
Crystal 1: Input to the inverting oscillator amplifier and input
to the internal clock generator circuits.
Crystal 2: Output from the inverting oscillator amplifier
SS
permits a power-on reset using only an
CC.
PP
) during EPROM
7