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 14342
Product data
7.2.4 Using the In-System Programming
P89LV51RB2/RC2/RD2 through the serial port. This firmware is provided by Philips
and embedded within each P89LV51RB2/RC2/RD2 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
connector needs 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 P89LV51RB2/RC2/RD2 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 P89LV51RB2/RC2/RD2 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
P89LV51RB2/RC2/RD2, 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 P89LV51RB2/RC2/RD2 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. 04 — 02 December 2004
Table
DD
, V
P89LV51RB2/RC2/RD2
12. As a record is received by the
SS
, TxD, RxD, and RST). Only a small
8-bit microcontrollers with 80C51 core
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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