P89CV51RC2FA NXP Semiconductors, P89CV51RC2FA Datasheet - Page 19

• Manufacturer Part Number: P89CV51RC2FA
• Description: MCU 8-Bit 89C 80C51 CISC 32KB Flash 5V 44-Pin PLCC Tube
• Manufacturer: NXP Semiconductors

Specifications of P89CV51RC2FA

• Package: 44PLCC
• Device Core: 80C51
• Family Name: 89C
• Maximum Speed: 40 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 32
• Interface Type: SPI/UART
• Number Of Timers: 3
• Ram Size: 1 KB
• Program Memory Size: 32 KB
• Program Memory Type: Flash
• Operating Temperature: -40 to 85 °C

NXP Semiconductors
P89CV51RB2_RC2_RD2_3
Product data sheet
6.3.7 Using ISP
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 P89CV51RB2/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
P89CV51RB2/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
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 P89CV51RB2/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>
Table
Rev. 03 — 25 August 2009
11. As a record is received by the P89CV51RB2/RC2/RD2, the
P89CV51RB2/RC2/RD2
80C51 with 1 kB RAM, SPI
© NXP B.V. 2009. All rights reserved.
19 of 76