80C51 8-bit microcontroller family
8K/256 OTP/ROM, expanded I/O
Preliminary specification
Supersedes data of 1997 Dec 29
IC20 Data Handbook
1998 Apr 23
Philips SemiconductorsPreliminary specification
80C51 8-bit microcontroller family
8K/256 OTP/ROM, expanded I/O
DESCRIPTION
The Philips 8XC453 is an I/O expanded single-chip microcontroller
fabricated with Philips high-density CMOS technology. Philips
epitaxial substrate minimizes latch-up sensitivity.
The 8XC453 is a functional extension of the 87C51 microcontroller
with three additional I/O ports and four I/O control lines. The 8XC453
is available in 68-pin LCC packages. Four control lines associated
with port 6 facilitate high-speed asynchronous I/O functions.
The 87C453 includes an 8k × 8 EPROM, a 256 × 8 RAM, 56 I/O
lines, two 16-bit timer/counters, a seven source, two priority level,
nested interrupt structure, a serial I/O port for either a full duplex
UART, I/O expansion, or multi-processor communications, and
on-chip oscillator and clock circuits.
The 87C453 has two software selectable modes of reduced activity
for further power reduction; idle mode and power-down mode. Idle
mode freezes the CPU while allowing the RAM, timers, serial port,
and interrupt system to continue functioning. Power-down mode
freezes the oscillator, causing all other chip functions to be
inoperative while maintaining the RAM contents.
83C453/87C453
FEA TURES
•80C51 based architecture
•Seven 8-bit I/O ports
•Port 6 features:
– Eight data pins
– Four control pins
– Direct MPU bus interface
– ISA Bus Interface
– Parallel printer interface
– IBF and OBF
– A flag latch on host write
•On the microcontroller:
– 8k × 8 EPROM
Quick pulse programming algorithm
Two-level program security system
– 256 × 8 RAM
– Two 16-bit counter/timers
– Two external interrupts
•External memory addressing capability
– 64k ROM and 64k RAM
•Low power consumption:
– Normal operation: less than 24mA at 5V , 16MHz
– Idle mode
– Power-down mode
P0.0–0.717-10I/OPort 0: Port 0 is an open-drain, bidirectional I/O port. Port 0 is also the multiplexed data and low-order
P1.0–P1.727-34I/OPort 1: Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. Port 1 receives the low-order address
P2.0–P2.72-9I/OPort 2: Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. Port 2 emits the high-order address
P3.0–P3.736-43I/OPort 3: Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. Port 3 can sink/source three LS TTL
P4.0–P4.3
P4.0–P4.726-19
P5.0–P5.744-51I/OPort 5: Port 5 is an 8-bit bidirectional I/O port with internal pull-ups. Port 5 can sink/source three LS TTL
P6.0–P6.759-66I/OPort 6: Port 6 is a specialized 8-bit bidirectional I/O port with internal pull-ups. This special port can
ODS55IODS: Output data strobe
IDS56IIDS: Input data strobe
BFLAG57I/OBFLAG: Bidirectional I/O pin with internal pull-ups
AFLAG58I/OAFLAG: Bidirectional I/O pin with internal pull-ups
RST35IReset: A high on this pin for two machine cycles while the oscillator is running, resets the device. An
ALE/PROG68I/OAddress Latch Enable/Program Pulse: Output pulse for latching the low byte of the address during an
PSEN67OProgram Store Enable: The read strobe to external program memory. PSEN is activated twice each
EA/V
PP
XTAL153ICrystal 1: Input to the inverting oscillator amplifier that forms the oscillator. This input receives the external
XTAL252OCrystal 2: An output of the inverting amplifier that forms the oscillator. This pin should be floated when an
PIN NO.
TYPE NAME AND FUNCTION
54IGround: 0V reference.
18IPower Supply: This is the power supply voltage for normal, idle, and power-down operation.
address bus during accesses to external memory. External pull-ups are required during program
verification. Port 0 can sink/source eight LS TTL inputs.
bytes during program memory verification. Port 1 can sink/source three LS TTL inputs, and drive CMOS
inputs without external pull-ups.
bytes during access to external memory and receives the high-order address bits and control signals
during program verification. Port 2 can sink/source three LS TTL inputs, and drive CMOS inputs without
external pull-ups.
inputs, and drive CMOS inputs without external pull-ups. Port 3 also serves the special functions listed
below:
36IRxD (P3.0): Serial input port
37OTxD (P3.1): Serial output port
38IINT0 (P3.2): External interrupt
39IINT1 (P3.3): External interrupt
40IT0 (P3.4): Timer 0 external input
41IT1 (P3.5): Timer 1 external input
42OWR (P3.6): External data memory write strobe
43ORD (P3.7): External data memory read strobe
I/O
Port 4: Port 4 is an 8-bit bidirectional I/O port with internal pull-ups. Port 4 can sink/source three LS TTL
I/O
inputs and drive CMOS inputs without external pull-ups.
inputs and drive CMOS inputs without external pull-ups.
sink/source three LS TTL inputs and drive CMOS inputs without external pull-ups. Port 6 can be used in a
strobed or non-strobed mode of operation. Port 6 works in conjunction with four control pins that serve the
functions listed below:
internal pull-down resistor permits a power-on reset using only an external capacitor connected to VCC.
access to external memory. ALE is activated at a constant rate of 1/6 the oscillator frequency except during
an external data memory access, at which time one ALE is skipped. ALE can sink/source three LS TTL
inputs and drive CMOS inputs without external pull-ups. This pin is also the program pulse during EPROM
programming.
machine cycle during fetches from external program memory. However, when executing out of external
program memory, two activations of PSEN
PSEN
is not activated during fetches from internal program memory. PSEN can sink/source eight LS TTL
inputs and drive CMOS inputs without an external pull-up. This pin should be tied low during programming.
1IInstruction Execution Control/Programming Supply Voltage: When EA is held high, the CPU executes
out of internal program memory, unless the program counter exceeds 1FFFH. When EA is held low, the
CPU executes out of external program memory. EA
the 12.75V programming supply voltage (V
oscillator when an external oscillator is used.
external oscillator is used.
are skipped during each access to external program memory.
must never be allowed to float. This pin also receives
* SFRs are bit addressable.
# SFRs are modified from or added to the 80C51 SFRs.
1. REset value depends on reset source.
1998 Apr 23
6
Philips SemiconductorsPreliminary specification
80C51 8-bit microcontroller family
8K/256 OTP/ROM, expanded I/O
IE REGISTERIP REGISTER
INT0
TF0
INT1
TF1
RI
TI
0
IT0
1
0
IT1
1
IE.0
IE.1
IE.2
IE.3
IE.4
83C453/87C453
HIGH PRIORITY
INTERRUPT
INTERRUPT
POLLING
SEQUENCE
IBF
OBF
IE.5
IE.6
INDIVIDUAL
ENABLES
GLOBAL
DISABLE
Figure 1. 8XC453 Interrupt Control System
LSBMSB
ET0EX1ET1ESIIBIOBEA
EX0
BITSYMBOLFUNCTION
IE.7EADisables all interrupts. If EA=0, no interrupt will be acknowledged. If EA=1, each interrupt
source is individually enabled or disabled by setting or clearing its enable bit.
IE.6IOBEnables or disables the Output Buffer Full (OBF) interrupt. If IOB=0, the interrupt is disabled,
If IOB=1, an interrupt will occur if EA is set and data has been read from the output buffer
register through Port 6 by the external host pulsing ODS low.
IE.5IIBEnables or disables the Input Buffer Full (IBF) interrupt. If IIB=0, the interrupt is disabled. If
IIB=1, an interrupt will occur if EA is set and data has been written into the Port 6 Input Data
Buffer by the host strobing IDS low .
IE.4ESEnables or disables the Serial Port Interrupt. If ES=0, the Serial Port Interrupt. If ES=0, the
Serial Port interrupt is disabled.
IE.3ET1Enables or disables the Timer 1 Overflow interrupt. If ET1=0, the Timer 1 interrupt is disabled.
IE.2EX1Enables or disables External Interrupt 1. If EX1=0, External Interrupt 1 is disabled.
IE.1ET0Enables or disables the Timer 0 Overflow interrupt. If ET0=0, the Timer 0 interrupt is disabled.
IE.0EX0Enables or disables External Interrupt 0. If EX0=0, external Interrupt 0 is disabled.
Figure 2. 8XC453 Interrupt Enable (IE) Register
SU00563
LOW PRIORITY
INTERRUPT
SU00562
1998 Apr 23
7
Philips SemiconductorsPreliminary specification
80C51 8-bit microcontroller family
83C453/87C453
8K/256 OTP/ROM, expanded I/O
LSBMSB
PT0PX1PT1PSPIBPOB—
BITSYMBOLFUNCTION
IP.7—Reserved.
IP.6POBDefines the Output Buffer Full interrupt (IOB) priority level. POB=1 programs it to the higher priority level.
IP.5PIBDefines the Input Buffer Full interrupt (IIB) priority level. PIB=1 programs it to the higher priority level.
IP.4PSDefines the Serial Port interrupt priority level. PS=1 programs it to the higher priority level.
IP.3PT1Defines the Timer 1 interrupt priority level. PT1=1 programs it to the higher priority level.
IP.2PX1Defines the External Interrupt 1 priority level. PX1=1 programs it to the higher priority level.
IP.1PT0Enables or disables the Timer 0 interrupt priority level. PT0=1 programs it to the higher priority level.
IP.0PX0Defines the External Interrupt 0 priority level. PX0=1 programs it to the higher priority level.
Figure 3. 8XC453 Interrupt Priority (IP) Register
PDGF0GF1POF—SMOD2SMOD1
PX0
01234567
IDLPCON (87H)
SU00564
BITSYMBOLFUNCTION
PCON.7SMOD1Double Baud rate bit. When set to a 1 and Timer 1 is used to generate baud rate, and the Serial Port
PCON.6SMOD0If set to 1, SCON.7 will be the Framing Error bit (FE). If PCON.6 is cleared, SCON.7 will be SM0.
PCON.5—Reserved.
PCON.4POFPower Off Flag is set during power on of V
PCON.3GF1General-purpose flag bit.
PCON.2GF0General-purpose flag bit.
PCON.1PDPower-Down bit. Setting this bit activates power-down mode. It can only be set if input EW is high.
PCON.0IDLIdle mode bit. Setting this bit activates the idle mode.
If logic 1s are written to PD and IDL at the same time, PD takes precedence.