AT89C51RB2 Atmel Corporation, AT89C51RB2 Datasheet - Page 95

• Manufacturer Part Number: AT89C51RB2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RB2

• Flash (kbytes): 16 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 1.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

ISP Protocol Description
Physical Layer
Frame Description
4180E–8051–10/06
The UART used to transmit information has the following configuration:
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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.
Table 70. 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
choosen by the host.
Record Mark:
–
Reclen:
–
Load Offset:
–
–
Record Type:
–
Data/Info:
–
Checksum:
–
1 byte
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.
Reclen
1 byte
Load Offset
2 bytes
Record Type
1 bytes
AT89C51RB2/RC2
Data or Info
n byte
Checksum
1 byte
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