P89LV51RD2BA PHILIPS [NXP Semiconductors], P89LV51RD2BA Datasheet - Page 21

• Manufacturer Part Number: P89LV51RD2BA
• Description: 8-bit 80C51 3 V low power 64 kB Flash microcontroller with 1 kB RAM
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9397 750 14101
Product data
7.2.4 Using the In-System Programming
P89LV51RD2 through the serial port. This firmware is provided by Philips and
embedded within each P89LV51RD2 device. The Philips In-System Programming
facility has made in-circuit programming in an embedded application possible with a
minimum of additional expense in components and circuit board area. The ISP
function uses five pins (V
to be available to interface your application to an external circuit in order to use this
feature.
The ISP feature allows for a wide range of baud rates to be used in your application,
independent of the oscillator frequency. It is also adaptable to a wide range of
oscillator frequencies. This is accomplished by measuring the bit-time of a single bit
in a received character. This information is then used to program the baud rate in
terms of timer counts based on the oscillator frequency. The ISP feature requires that
an initial character (an uppercase U) be sent to the P89LV51RD2 to establish the
baud rate. The ISP firmware provides auto-echo of received characters. Once baud
rate initialization has been performed, the ISP firmware will only accept Intel Hex-type
records. Intel Hex records consist of ASCII characters used to represent hexadecimal
values and are summarized below:
In the Intel Hex record, the ‘NN’ represents the number of data bytes in the record.
The P89LV51RD2 will accept up to 32 data bytes. The ‘AAAA’ string represents the
address of the first byte in the record. If there are zero bytes in the record, this field is
often set to 0000. The ‘RR’ string indicates the record type. A record type of ‘00’ is a
data record. A record type of ‘01’ indicates the end-of-file mark. In this application,
additional record types will be added to indicate either commands or data for the ISP
facility.
The maximum number of data bytes in a record is limited to 32 (decimal). ISP
commands are summarized in
the information in the record is stored internally and a checksum calculation is
performed. The operation indicated by the record type is not performed until the
entire record has been received. Should an error occur in the checksum, the
P89LV51RD2 will send an ‘X’ out the serial port indicating a checksum error. If the
checksum calculation is found to match the checksum in the record, then the
command will be executed. In most cases, successful reception of the record will be
indicated by transmitting a ‘.’ character out the serial port.
:NNAAAARRDD..DDCC<crlf>
Rev. 03 — 11 October 2004
DD
, V
SS
Table
, TxD, RxD, and RST). Only a small connector needs
12. As a record is received by the P89LV51RD2,
8-bit microcontrollers with 80C51 core
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
P89LV51RD2
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