AT89C51ID2-SMSIM ATMEL [ATMEL Corporation], AT89C51ID2-SMSIM Datasheet - Page 126

• Manufacturer Part Number: AT89C51ID2-SMSIM
• Description: 8-bit Flash Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

ISP Protocol Description
Physical Layer
Frame Description
126
AT89C51ID2
The UART used to transmit information has the following configuration:
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•
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•
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The Serial Protocol is based on the Intel Hex-type records.
Intel Hex records consist of ASCII characters used to represent hexadecimal values and
are summarized below
Figure 50. Intel Hex Type Frame
•
Record Mark is the start of frame. This field must contain ’:’.
•
Reclen 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 (see Section “ISP Commands Summary”).
•
Record Type specifies the command type. This field is used to interpret the remaining
information within the frame. The encoding for all the current record types is described
in Section “ISP Commands Summary”.
•
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.
•
The two’s complement of the 8-bit bytes that result from converting each pair of ASCII
hexadecimal digits to one byte of binary, and including the Reclen field to and including
the last byte of the Data/Info field. Therefore, the sum of all the ASCII pairs in a record
after converting to binary, from the Reclen field to and including the Checksum field, is
zero.
Character: 8-bit data
Parity: none
Stop: 2 bits
Flow control: none
Baudrate: autobaud is performed by the bootloader to compute the baudrate
choosen by the host.
Record Mark:
Reclen:
Load Offset:
Record Type:
Data/Info:
Checksum:
Record
1-byte
Mark
’:’
Reclen
1-byte
2-bytes
Load
Offset
1-byte
Record
Type
n-bytes
Data
Info
or
Checksum
1-byte
4289A–8051–09/03