P87LPC764BD NXP Semiconductors, P87LPC764BD Datasheet - Page 34
P87LPC764BD
Manufacturer Part Number
P87LPC764BD
Description
MCU 8-Bit 87LP 80C51 CISC 4KB EPROM 5V 20-Pin SO Tube
Manufacturer
NXP Semiconductors
Datasheet
1.P87LPC764BD512.pdf
(60 pages)
Specifications of P87LPC764BD
Package
20SO
Device Core
80C51
Family Name
87LP
Maximum Speed
20 MHz
Ram Size
128 Byte
Program Memory Size
4 KB
Operating Supply Voltage
5 V
Data Bus Width
8 Bit
Program Memory Type
EPROM
Number Of Programmable I/os
18
Interface Type
I2C/UART
Operating Temperature
0 to 70 °C
Number Of Timers
2
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
P87LPC764BD
Manufacturer:
PHILIPS/飞利浦
Quantity:
20 000
Company:
Part Number:
P87LPC764BDH
Manufacturer:
NXP
Quantity:
2 500
Company:
Part Number:
P87LPC764BDH
Manufacturer:
MIC
Quantity:
2 500
Part Number:
P87LPC764BDH
Manufacturer:
NXP/恩智浦
Quantity:
20 000
Company:
Part Number:
P87LPC764BDH,512
Manufacturer:
NXP
Quantity:
747
Philips Semiconductors
Baud Rates
The baud rate in Mode 0 is fixed: Mode 0 Baud Rate = CPU clock/6.
The baud rate in Mode 2 depends on the value of bit SMOD1 in
Special Function Register PCON. If SMOD1 = 0 (which is the value
on reset), the baud rate is 1/32 of the CPU clock frequency. If
SMOD1 = 1, the baud rate is 1/16 of the CPU clock frequency.
Using Timer 1 to Generate Baud Rates
When Timer 1 is used as the baud rate generator, the baud rates in
Modes 1 and 3 are determined by the Timer 1 overflow rate and the
value of SMOD1. The Timer 1 interrupt should be disabled in this
Table 9. Baud Rates, Timer Values, and CPU Clock Frequencies for SMOD1 = 0
2003 Sep 03
Low power, low price, low pin count (20 pin)
microcontroller with 4 kbyte OTP
Timer Co nt
Timer Count
Mode 2 Baud Rate + 1 ) SMOD1
–10
–1
–2
–3
–4
–5
–6
–7
–8
–9
* 1.8432
* 3.6864
0.4608
0.9216
1.3824
2.3040
2.7648
3.2256
4.1472
4.6080
2400
32
CPU clock frequency
* 3.6864
* 7.3728
0.9216
1.8432
2.7648
4.6080
5.5296
6.4512
8.2944
9.2160
4800
* 14.7456
* 18.4320
* 11.0592
* 1.8432
* 3.6864
* 7.3728
12.9024
16.5888
5.5296
9.2160
9600
33
application. The Timer itself can be configured for either “timer” or
“counter” operation, and in any of its 3 running modes. In the most
typical applications, it is configured for “timer” operation, in the
auto-reload mode (high nibble of TMOD = 0010b). In that case the
baud rate is given by the formula:
Tables 6 and 7 list various commonly used baud rates and how they
can be obtained using Timer 1 as the baud rate generator.
Baud Rate
Mode 1, 3 Baud Rate +
* 11.0592
* 14.7456
* 18.4320
* 3.6864
* 7.3728
19.2k
–
–
–
–
–
* 14.7456
* 7.3728
38.4k
192 (or 96 if SMOD1 + 1)
–
–
–
–
–
–
–
–
CPU clock frequency
256 * (TH1)
P87LPC764
* 11.0592
57.6k
Product data
–
–
–
–
–
–
–
–