PROGRAM MEMORY Up to 16 Kbytes of the program memory can reside in the on-chip EPROM The device
can also address up to 64K of program memory external to the chip
DATA MEMORY This microcontroller has a 256 x 8 on-chip RAM In addition it can address up to 64 Kbytes of
external data memory
The Intel 87C54 is a single-chip control-oriented microcontroller which is fabricated on Intel’s reliable
CHMOS EPROM technology Being a member of the MCS-51 family the 87C54 uses the same powerful
instruction set has the same architecture and is pin-for-pin compatible with the existing MCS-51 family of
products The 87C54 is an enhanced version of the 87C51FB Its added features of 16 Kbytes of program
memory make it an even more powerful microcontroller for applications that require High Speed I O and
up down counting capabilities such as brake and traction control
Other brands and names are the property of their respective owners
Information in this document is provided in connection with Intel products Intel assumes no liability whatsoever including infringement of any patent or
copyright for sale and use of Intel products except as provided in Intel’s Terms and Conditions of Sale for such products Intel retains the right to make
changes to these specifications at any time without notice Microcomputer Products may have minor variations to this specification known as errata
COPYRIGHT
INTEL CORPORATION 1995
February 1994
Order Number 270849-004
AUTOMOTIVE 87C54 87C54-20
270849 –1
Figure 1 87C54 Block Diagram
2
AUTOMOTIVE 87C54 87C54-20
characteristics are guaranteed over the temperature
range of
b
40 C to
a
85 C ambient For the automo-
tive temperature range option operational charac-
teristics are guaranteed over the temperature range
of
b
40 C to
a
125 C ambient The automotive ex-
tended and commercial temperature versions of the
MCS-51 product families are available with or with-
out burn-in options
As shown in Figure 2 temperature burn-in and
package options are identified by a one- or two-letter
prefix to the part number
87C54 PRODUCT OPTIONS
Intel’s extended and automotive temperature range
products are designed to meet the needs of those
applications whose operating requirements exceed
commercial standards
With the commercial standard temperature range
operational characteristics are guaranteed over the
temperature range of 0 C to
a
70 C ambient With
the extended temperature range option operational
270849 – 4
Example
AN87C54 indicates an automotive temperature range version of the 87C54 in a PLCC package with 16 Kbyte EPROM program memory
Figure 2 Package Options
Table 1 Temperature Options
Temperature
Classification
Extended
Automotive
Temperature
Designation
T
L
A
B
Operating
Temperature
C Ambient
b
40 to
a
85
b
40 to
a
85
b
40 to
a
125
b
40 to
a
125
Burn-In
Options
Standard
Extended
Standard
Extended
3
AUTOMOTIVE 87C54 87C54-20
Port 0 Port 0 is an 8-bit open drain bidirectional I O
port As an output port each pin can sink several LS
TTL inputs Port 0 pins that have 1’s written to them
float and in that state can be used as high-imped-
ance 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 inter-
nal pullups when emitting1’s and can source and
sink several LS TTL inputs
Port 0 also receives the code bytes during EPROM
programming and outputs the code bytes during
program verification External pullup resistors are re-
quired during program verification
Port 1 Port 1 is an 8-bit bidirectional I O port with
internal pullups The Port 1 output buffers can drive
LS TTL inputs Port 1 pins that have 1’s written to
them are pulled high by the internal pullups and in
that state can be used as inputs As inputs Port 1
pins that are externally pulled low will source current
(I
IL
on the data sheet) because of the internal pull-
ups
270849 –2
PACKAGES
Part
87C54
87C54
Prefix
AP
AN
Package Type
40-Pin Plastic DIP
44-Pin PLCC
DIP (PDIP)
In addition Port 1 serves the functions of the follow-
ing special features of the 87C54
Port Pin
P1 0
P1 1
P1 2
P1 3
P1 4
P1 5
Alternate Function
T2 (External Count Input to Timer
Counter 2) Clock-Out
T2EX (Timer Counter 2 Capture
Reload Trigger and Direction Control)
ECI (External Count Input to the PCA)
CEX0 (External I O for Compare
Capture Module 0)
CEX1 (External I O for Compare
Capture Module 1)
CEX2 (External I O for Compare
Capture Module 2)
CEX3 (External I O for Compare
Capture Module 3)
CEX4 (External I O for Compare
Capture Module 4)
270849 –3
Do not connect reserved pins
P1 6
P1 7
PAD (PLCC)
Figure 3 Pin Connections
PIN DESCRIPTIONS
V
CC
Supply voltage
V
SS
Circuit ground
V
SS1
Secondary ground (in PLCC only) Provided to
reduce ground bounce and improve power supply
by-passing
NOTE
This pin is not a substitute for the V
SS
pin (pin 22)
4
Port 1 receives the low-order address bytes during
EPROM programming and verifying
Port 2 Port 2 is an 8-bit bidirectional I O port with
internal pullups The Port 2 output buffers can drive
LS TTL inputs Port 2 pins that have 1’s written to
them are pulled high by the internal pullups and in
that state can be used as inputs As inputs Port 2
pins that are externally pulled low will source current
(I
IL
on the data sheet) because of the internal pull-
ups
AUTOMOTIVE 87C54 87C54-20
Port 2 emits the high-order address byte during
fetches from external Program Memory and during
accesses to external Data Memory that use 16-bit
addresses (MOVX DPTR) In this application it
uses strong internal pullups when emitting 1’s Dur-
ing accesses to external Data Memory that use 8-bit
addresses (MOVX Ri) Port 2 emits the contents of
the P2 Special Function Register
Some Port 2 pins receive the high-order address bits
during EPROM programming and program verifica-
tion
Port 3 Port 3 is an 8-bit bidirectional I O port with
internal pullups The Port 3 output buffers can drive
LS TTL inputs Port 3 pins that have 1’s written to
them are pulled high by the internal pullups and in
that state can be used as inputs As inputs Port 3
pins that are externally pulled low will source current
(I
IL
on the data sheet) because of the pullups
Port 3 also serves the functions of various special
features of the MCS-51 Family as listed below
Port Pin
P3 0
P3 1
P3 2
P3 3
P3 4
P3 5
P3 6
P3 7
Alternate Function
RXD (serial input port)
TXD (serial output port)
INT0 (external interrupt 0)
INT1 (external interrupt 1)
T0 (Timer 0 external input)
T1 (Timer 1 external input)
WR (external data memory write strobe)
RD (external data memory read strobe)
In normal operation ALE is emitted at a constant
rate of
the oscillator frequency and may be used
for external timing or clocking purposes Note how-
ever that one ALE pulse is skipped during each ac-
cess to external Data Memory
Throughout the remainder of this data sheet ALE
will refer to the signal coming out of the ALE PROG
pin and the pin will be referred to as the ALE PROG
pin
PSEN Program Store Enable is the read strobe to
external Program Memory
When the 87C54 is executing code from external
Program Memory PSEN is activated twice each
machine cycle except that two PSEN activations
are skipped during each access to external Data
Memory
EA V
PP
External Access enable EA must be
strapped to VSS in order to enable the device to
fetch code from external Program Memory locations
0000H to 0FFFFH Note however that if any of the
Lock bits are programmed EA will be internally
latched on reset
EA should be strapped to V
CC
for internal program
executions
This pin also receives the programming supply volt-
age (V
PP
) during EPROM programming
XTAL1 Input to the inverting oscillator amplifier
In addition some Port 3 pins receive the high-order
address bits and act as control signals during
EPROM programming and programming verification
RST Reset input A high on this pin for two machine
cycles while the oscillator is running resets the de-
vice The port pins will be driven to their reset condi-
tion when a minimum V
IH1
is applied whether the
oscillator is running or not An internal pulldown re-
sistor permits a power-on reset with only a capacitor
connected to V
CC
ALE Address Latch Enable output pulse for latching
the low byte of the address during accesses to ex-
ternal memory This pin (ALE PROG) is also the
program pulse input during EPROM programming for
the 87C54
XTAL2 Output from the inverting oscillator amplifier
OSCILLATOR CHARACTERISTICS
XTAL1 and XTAL2 are the input and output respec-
tively of a inverting amplifier which can be config-
ured for use as an on-chip oscillator as shown in
Figure 4 Either a quartz crystal or ceramic resonator
may be used More detailed information concerning
the use of the on-chip oscillator is available in Appli-
cation Note AP-155 ‘‘Oscillators for Microcontrol-
GD32 MCU
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