Philips Semiconductors
Preliminary specification
Low pin count single-chip 8-bit microcontrollers
87LPC764
TABLE OF CONTENTS
General Description . . . . . . . . . . . . . . . . . . . . . . . .
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
3
Ordering Information . . . . . . . . . . . . . . . . . . . . . . .
Pin Configuration,
20–Pin DIP and SO Packages . . . . . . . . . . . . . . .
Logic Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Function Registers . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . .
Enhanced CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comparator Configuration . . . . . . . . . . . . . . . . . . . . . . . . . .
Internal Reference Voltage . . . . . . . . . . . . . . . . . . . . . . . . .
Comparator Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comparators and Power Reduction Modes . . . . . . . . . . .
Comparator Configuration Example . . . . . . . . . . . . . . . . . .
I
2
C Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I
2
C Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reading I2CON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking ATN and DRDY . . . . . . . . . . . . . . . . . . . . . . . . . .
Writing I2CON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regarding Transmit Active . . . . . . . . . . . . . . . . . . . . . . . . .
Regarding Software Response Time . . . . . . . . . . . . . . . . .
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Interrupt Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quasi–Bidirectional Output Configuration . . . . . . . . . . . . .
Open Drain Output Configuration . . . . . . . . . . . . . . . . . . . .
Push–Pull Output Configuration . . . . . . . . . . . . . . . . . . . . .
Keyboard Interrupt (KBI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Speed Oscillator Option . . . . . . . . . . . . . . . . . . . . . . . .
Medium Speed Oscillator Option . . . . . . . . . . . . . . . . . . . .
High Speed Oscillator Option . . . . . . . . . . . . . . . . . . . . . . .
On–Chip RC Oscillator Option . . . . . . . . . . . . . . . . . . . . . .
External Clock Input Option . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CPU Clock Modification: CLKR and DIVM . . . . . . . . . . . .
4
4
4
5
6
7
9
9
9
9
9
11
11
11
11
12
12
12
14
14
14
15
16
17
18
18
19
19
20
22
22
22
22
22
22
22
23
Power Monitoring Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brownout Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power On Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Reduction Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idle Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Voltage EPROM Operation . . . . . . . . . . . . . . . . . . . . .
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timer/Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timer Overflow Toggle Output . . . . . . . . . . . . . . . . . . . . . .
UART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Serial Port Control Register (SCON) . . . . . . . . . . . . . . . . .
Baud Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Timer 1 to Generate Baud Rates . . . . . . . . . . . . . .
More About UART Mode 0 . . . . . . . . . . . . . . . . . . . . . . . . .
More About UART Mode 1 . . . . . . . . . . . . . . . . . . . . . . . . .
More About UART Modes 2 and 3 . . . . . . . . . . . . . . . . . . .
Multiprocessor Communications . . . . . . . . . . . . . . . . . . . .
Automatic Address Recognition . . . . . . . . . . . . . . . . . . . . .
Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Watchdog Feed Sequence . . . . . . . . . . . . . . . . . . . . . . . . .
Watchdog Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Software Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dual Data Pointers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EPROM Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Configuration Bytes . . . . . . . . . . . . . . . . . . . . . . . .
Security Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
23
24
24
24
24
26
26
27
28
29
29
29
30
30
30
30
30
30
31
32
32
34
34
37
37
40
40
40
40
42
42
42
43
43
44
Absolute Maximum Ratings . . . . . . . . . . . . . . . . .
DC Electrical Characteristics . . . . . . . . . . . . . . . .
Comparator Electrical Characteristics . . . . . . .
AC Electrical Characteristics . . . . . . . . . . . . . . . .
44
45
46
47
1999 Mar 11
2
Philips Semiconductors
Preliminary specification
Low pin count single-chip 8-bit microcontrollers
87LPC764
GENERAL DESCRIPTION
The 87LPC764 is a 20-pin single-chip microcontroller designed for
low pin count applications demanding high-integration, low cost
solutions over a wide range of performance requirements. A
member of the Philips low pin count family, the 87LPC764 offers
programmable oscillator configurations for high and low speed
crystals or RC operation, wide operating voltage range,
programmable port output configurations, selectable Schmitt trigger
inputs, LED drive outputs, and a built-in watchdog timer. The
87LPC764 is based on an accelerated 80C51 processor
architecture that executes instructions at twice the rate of standard
80C51 devices.
•
Active low reset. On-chip power-on reset allows operation with no
external reset components.
•
Low voltage reset. One of two preset low voltage levels may be
selected to allow a graceful system shutdown when power fails.
May optionally be configured as an interrupt.
•
Oscillator Fail Detect. The watchdog timer has a separate fully
on-chip oscillator, allowing it to perform an oscillator fail detect
function.
•
Configurable on-chip oscillator with frequency range and RC
oscillator options (selected by user programmed EPROM bits).
The RC oscillator option allows operation with no external
oscillator components.
FEATURES
•
An accelerated 80C51 CPU provides instruction cycle times of
300–600ns for all instructions except multiply and divide when
executing at 20 MHz. Execution at up to 20 MHz when
V
DD
= 4.5V to 6.0V, 10 MHz when V
DD
= 2.7V to 4.5V.
•
Programmable port output configuration options:
quasi-bidirectional, open drain, push-pull, input-only.
•
2.7V to 6.0V operating range for digital functions.
•
4K bytes EPROM code memory.
•
128 byte RAM data memory.
•
Two 16-bit counter/timers. Each timer may be configured to toggle
a port output upon timer overflow.
•
Selectable Schmitt trigger port inputs.
•
LED drive capability (20mA) on all port pins.
•
Controlled slew rate port outputs to reduce EMI. Outputs have
approximately a 10 ns minimum ramp times.
•
15 I/O pins minimum. Up to 18 I/O pins using on-chip oscillator
and reset options.
•
Only power and ground connections are required to operate the
87LPC764 when fully on-chip oscillator and reset options are
selected.
•
Two analog comparators.
•
Full duplex UART.
•
I
2
C communication port.
•
Eight keypad interrupt inputs, plus two additional external interrupt
inputs.
•
Serial EPROM programming allows simple in-circuit production
coding. Two EPROM security bits prevent reading of sensitive
application programs.
•
Idle and Power Down reduced power modes. Improved wakeup
from Power Down mode (a low interrupt input starts execution).
Typical Power Down current is 1µA.
•
Four interrupt priority levels.
•
Watchdog timer with separate on-chip oscillator, requiring no
external components. The watchdog timeout time is selectable
from 8 values.
•
Extended temperature range: –40 to +85°C.
•
20-pin DIP and SO packages.
1999 Mar 11
3
京公网安备 11010802033920号
EEWORLD
