89C5121-SK1 Atmel, 89C5121-SK1 Datasheet - Page 69

• Manufacturer Part Number: 89C5121-SK1
• Description: KIT SMART CARD FOR AT89C5121
• Manufacturer: Atmel
• Type: Smart Cardr

Specifications of 89C5121-SK1

• Contents: Board
• For Use With/related Products: AT89C5121
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: T89C5121-SK1; T89C5121-SK1

UART Protocol
Overview
Physical Layer
Datas and Limits
Frame Description
4164G–SCR–07/06
Table 49. Valid Software Security Byte Values
The serial protocol used is described below.
The UART is used to transmit information with the following configuration:
•
•
•
•
•
As described in Section “Transfer Checks”, the downloaded program include the CRC
values in the last two upper bytes of the 16K bytes space.
An update of a part of the 16K program cannot be done because the CRC value would
have to be updated with a value which depends of the actual value of the rest of the
program.
So the Program function of the PC Software Tool include the individual program com-
mands (with 64 data bytes) from address 0000h to address 3FFFh.
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 50. Intel Hex Type Frame
•
•
•
SSB Values
FE
FC
BF,BE,BC
7F,7E,7C
3F,3E,3C
Record Mark ‘:’
Character: 8-bit data
Parity: none
Stop: 1 bit
Flow control: none
Baudrate: autobaud is performed by the bootloader to compute the baudrate
chosen by the host.
Record Mark:
–
Reclen:
–
Load Offset:
–
1-byte
Record Mark is the start of frame. This field must contain’:’.
Reclen specifies that the number of bytes of information or data that follow
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 Program Data Record (see Table 51).
1-byte = 40h
Reclen
Load Offset
Functions
No bypass and level1 security
No bypass and level2 security
UART bypass and security levels
External TWI bypass and security levels
UART and Ext. TWI bypass
2-byte
Record Type
1-byte
Data or Info
64-byte
A/T8xC5121
Checksum
1-byte
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