P87LPC768BD,512 NXP Semiconductors, P87LPC768BD,512 Datasheet - Page 14

• Manufacturer Part Number: P87LPC768BD,512
• Description: IC 80C51 MCU 4K OTP 20-SOIC
• Manufacturer: NXP Semiconductors
• Series: LPC700r

Specifications of P87LPC768BD,512

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, POR, PWM, WDT
• Number Of I /o: 18
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: A/D 4x8b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 20-SOIC (7.5mm Width)
• Processor Series: P87LPC7x
• Core: 80C51
• Data Bus Width: 8 bit
• Data Ram Size: 128 B
• Interface Type: I2C, UART
• Maximum Clock Frequency: 10 MHz, 20 MHz
• Number Of Programmable I/os: 18
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: 0 C
• On-chip Adc: 8 bit, 4 Channel
• For Use With: OM10063 - PROGRAMMER LPC700 P76XLCPOM10050 - EMULATOR LPC700 PDS76X
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 568-3218-5; 935267360512; P87LPC768BD

Philips Semiconductors
Code Examples for the A/D
The first piece of sample code shows an example of port configuration for use with the A/D. This example sets up the pins so that all four A/D
channels may be used. Port configuration for analog functions is described in the section Analog Functions.
Following is an example of using the A/D with interrupts. The routine ADStart begins an A/D conversion using the A/D channel number supplied
in the accumulator. The channel number is not checked for validity. The A/D must previously have been enabled with sufficient time to allow for
stabilization.
The interrupt handler routine reads the conversion value and returns it in memory address ADResult. The interrupt should be enabled prior to
starting the conversion.
Following is an example of using the A/D with polling. An A/D conversion is started using the channel number supplied in the accumulator. The
channel number is not checked for validity. The A/D must previously have been enabled with sufficient time to allow for stabilization. The
conversion result is returned in the accumulator.
2002 Mar 12
Low power, low price, low pin count (20 pin) microcontroller
with 4 kB OTP 8-bit A/D, Pulse Width Modulator
; Set up port pins for A/D conversion, without affecting other pins.
; Start A/D conversion.
ADStart:
;
;
; A/D interrupt handler.
ADInt:
ADRead:
ADChk:
mov
anl
orl
orl
setb
orl
orl
ret
push
mov
mov
clr
anl
pop
reti
orl
setb
jnb
mov
clr
anl
ret
PT0AD,#78h
P0M2,#87h
P0M1,#78h
ADCON,A
ADCS
PCON,#01h
PCON,#02h
ACC
A,DAC0
ADResult,A
ADCI
ADCON,#0fch
ACC
ADCON,A
ADCS
ADCI,ADChk
A,DAC0
ADCI
ADCON,#0fch
; Disable digital inputs on A/D input pins.
; Disable digital outputs on A/D input pins.
; Disable digital outputs on A/D input pins.
; Add in the new channel number.
; Start an A/D conversion.
; The CPU could be put into Idle mode here.
; The CPU could be put into Power Down mode here if RCCLK = 1.
; Save accumulator.
; Get A/D result,
;
; Clear the A/D completion flag.
; Clear the A/D channel number.
; Restore accumulator.
; Add in the new channel number.
; Start A/D conversion.
; Wait for ADCI to be set.
; Get A/D result.
; Clear the A/D completion flag.
; Clear the A/D channel number.
and save it in memory.
12
P87LPC768
Preliminary data