IC89C54 Datasheet, PDF (5/24 Pages) Integrated Circuit Solution Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER with 16/32/64-Kbytes of FLASH

IC89C54/58/64
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
P2.0-P2.7
1
2
21-28
2
3
24-31
40
I
41
I
18-25 I/O
Integrated Circuit Solution Inc.
MC009-0B
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 FFFFH. If EA# is held high, the device executes from internal
program memory unless the program counter contains an address
grater than 3FFFH/7FFFH respecting to IC89C54/58 and the device
always executes internal program memory in IC89C64.
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 open-drain, bi-directional 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
memory program and verification, and outputs the code bytes
during program verification. External pullups are required dur-
ing program verification.
Port 1: Port 1 is an 8-bit bi-directional I/O port with internal pull-
ups. 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.
Port 1 also receives the low-order address byte during memory
program and verification.
T2(P1.0) : Timer/counter 2 external count input.
T2EX(P1.1): Timer/counter 2 trigger input.
Port 2: Port 2 is an 8-bit bi-directional I/O port with internal pull-
ups. 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. Port 2 emits the high order address byte
during fetches from external program memory and during
accesses to external data memory that used 16-bit addresses.
In this application, it uses strong internal pullups when emitting
1s. During accesses to external data memory that use 8-bit
addresses, port 2 emits the contents of the P2 special function
register.
Port 2 also receives the high-order address bits from A13 to A8
and some control signals during Flash programming and
verification. P2.6, P2.7 are the control signals while the chip
programs and erases. P2.6 is a program command strobe
signal. P2.7 is a data output enable signal.
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