IC89LV52 Datasheet, PDF (5/22 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
Symbol PDIP
ALE/PROG 30
PLCC
33
PQFP I/O
27 I/O
EA/VPP
31
35
29
I
P0.0-P0.7 39-32
43-36
37-30 I/O
P1.0-P1.7 1-8
2-9
40-44 I/O
1-3
P2.0-P2.7
1
2
21-28
2
3
24-31
40
I
41
I
18-25 I/O
Integrated Circuit Solution Inc.
MC010-0D 11/16/2001
Name and Function
Address Latch Enable: Output pulse for latching the low byte
of the address during an address to the external memory. In
normal operation, ALE is emitted at a constant rate of 1/6 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 Flash programming.
External access enable: EA must be externally held low to
enable the device to fetch code from external program memory
locations 0000H to 1FFFH. If EA is held high, the device
executes from internal program memory unless the program
counter contains an address grater than 1FFFH. IC89C51A
internal Programming memory range is from 0000-0FFFH.
This is also receives the 12 V programming enable voltage
(Vpp) during Flash programming, when 12 V programming is
selected.
Port 0: Port 0 is an 8-bit open-drain, bidirectional I/O port. Port
0 pins that have 1s written to them float and can be used as high-
impedance inputs. Port 0 is also the multiplexed low-order
address and data bus during accesses to external program and
data memory. In this application, it uses strong internal pullups
when emitting 1s.
Port 0 also receives the command and code bytes during
programmable memory programming and outputs the code
bytes during program verification. External pullups are required
during program verification.
Port 1: Port 1 is an 8-bit bidirectional I/O port with internal
pullups. Port 1 pins that have 1s written to them are pulled high
by the internal pullups and can be used as inputs. As inputs, Port
1 pins that are externally pulled low will source current because
of the internal pullups. (See DC Characteristics: IIL). The Port 1
output buffers can sink/source four TTL inputs.
Port 1 also receives the low-order address byte during Flash
programming and verification.
T2(P1.0): Timer/Counter 2 external count input.(IC89LV52A only)
T2EX(P1.1): Timer/Counter 2 trigger input.(IC89LV52A only)
Port 2: Port 2 is an 8-bit bidirectional I/O port with internal
pullups. Port 2 pins that have 1s written to them are pulled high
by the internal pullups and can be used as inputs. As inputs, Port
2 pins that are externally pulled low will source current because
of the internal pullups. (See DC Characteristics: IIL). Port 2 emits
the high order address byte during fetches from external pro-
gram memory and during accesses to external data memory
that used 16-bit addresses (MOVX @ DPTR). In this application,
Port 2 uses strong internal pullups when emitting 1s. During
accesses to external data memory that use 8-bit addresses
(MOVX @ Ri [i = 0, 1]), Port 2 emits the contents of the P2
Special Function Register.
Port 2 also receives the high-order bits and some control signals
during Flash programming and verification. P2.6 is a program
command strobe signal. P2.7 is a data output enable signal.
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