IC89LV52 Datasheet, PDF (6/22 Pages) Integrated Circuit Solution Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER with 8(4)-Kbytes of FLASH

IC89LV52(51)A
Table 1. Detailed Pin Description (continued)
Symbol PDIP
P3.0-P3.7 10-17
PLCC
11, 13-19
PQFP I/O
5, 7-13 I/O
10
11
5
I
11
13
7
O
12
14
8
I
13
15
9
I
14
16
10
I
15
17
11
I
16
18
12
O
17
19
13
O
PSEN
29
32
26
O
RST
9
10
4
I
XTAL 1
19
21
15
I
XTAL 2
18
20
14
O
GND
20
22
16
I
Vcc
40
44
38
I
Name and Function
Port 3: Port 3 is an 8-bit bidirectional I/O port with internal
pullups. Port 3 pins that have 1s written to them are pulled high
by the internal pullups and can be used as inputs. As inputs, Port
3 pins that are externally pulled low will source current because
of the internal pullups. (See DC Characteristics: IIL).
Port 3 also serves the special features of the IC89LV52(51)A, as
listed below:
RxD (P3.0): Serial input port.
TxD (P3.1): Serial output port.
INT0 (P3.2): External interrupt 0.
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.
Program control signal while the chip programs and erases.
RD (P3.7): External data memory read strobe.
Program control signal while the chip programs and erases.
Program Store Enable: The read strobe to external program
memory. When the device is 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.
PSEN is an input control signal while memory program and
verification.
Reset: A high on this pin for two machine cycleswhile the
oscillator is running resets the device. An internal resistor to
GND permits a power-on reset using only an external capacitor.
A small internal resistor permits power-on reset using only a
capacitor connected to VCC.
RST is an input control signal during memory program and
verification.
Crystal 1: Input to the inverting oscillator amplifier and input
to the internal clock generator circuits.
Crystal 2: Output from the inverting oscillator amplifier.
Ground: 0V reference.
Power Supply: This is the power supply voltage for operation.
6
Integrated Circuit Solution Inc.
MC010-0D 11/16/2001