at89c51re2-slsem ATMEL Corporation, at89c51re2-slsem Datasheet - Page 56

• Manufacturer Part Number: at89c51re2-slsem
• Description: At89c51re2 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

ISP Protocol Description
Physical Layer
Frame Description
7663B–8051–03/07
The UART used to transmit information has the following configuration:
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The Serial Protocol is based on the Intel Extended Hex-type records.
Intel Hex records consist of ASCII characters used to represent hexadecimal values and
are summarized below.
Table 24. Intel Hex Type Frame
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Record Mark ‘:’
Character: 8-bit data
Parity: none
Stop: 1 bit
Flow control: none
Baud rate: autobaud is performed by the bootloader to compute the baud rate
chosen by the host.
Record Mark:
–
Record length:
–
Load Offset:
–
–
Record Type:
–
Data/Info:
–
Checksum:
–
1 byte
Record Mark is the start of frame. This field must contain ’:’.
Record length specifies the number of Bytes of information or data which
follows the Record Type field of the record.
Load Offset specifies the 16-bit starting load offset of the data Bytes,
therefore this field is used only for
Data Program Record.
Record Type specifies the command type. This field is used to interpret the
remaining information within the frame.
Data/Info is a variable length field. It consists of zero or more Bytes encoded
as pairs of hexadecimal digits. The meaning of data depends on the Record
Type.
Checksum is the two’s complement of the 8-bit Bytes that result from
converting each pair of ASCII hexadecimal digits to one Byte of binary, thus
including all field from the Record Length field to the last Byte of the
Data/Info field. Therefore, the sum of all the ASCII pairs in a record after
converting to binary, including all field from the Record Length field to the
Checksum field, is zero.
Record length
1 byte
Load Offset
2 bytes
Record Type
1 bytes
Data or Info
n byte
Checksum
1 byte
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