Atmel ATSTK500 500 Starter kit and development system. ATSTK500 ATSTK500 Datenbogen

 

2591C-AVR-06/06 

The table describes all states, events and conditions for the handling of incoming 
data. 

Read character from 
inbuf 

Char == ASCII 27 

 

Get Sequence Number 

Read character from 
inbuf 

Char != ASCII 27 

Update statistics 

Start 

Start 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

Received sequence 
number == Sent 
sequence number 

 

Get Message Size 

Read character from 
inbuf 

Received sequence 
number != Sent 
sequence number 

Update statistics 

Start 

Get Sequence Number 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

 

 

Get Message Size 2 

Get Message Size 1 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

 

Calculate message size 

Get Token 

Get Message Size 2 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

Char == ASCII 14 

 

Get Data 

Read character from 
inbuf 

Char != ASCII 14 

Update statistics 

Start 

Get Token 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

Nmb char read == 
MESSAGE_SIZE 

 Get 

Checksum 

Read character from 
inbuf 

Nmb char read < 
MESSAGE_SIZE 

 Get 

Data 

Get Data 

Total timeout 

 

Exit with error 

 

Read character from 
inbuf 

Checksum OK 

 

Read character from 
inbuf 

Checksum NOT OK 

Update statistics 

Start 

Get Checksum 

Total timeout 

 

Exit with error 

 

 

The state machine on the STK500 side, which receives incoming packets from the 
PC, is similar apart from that there is no total timeout in the reception.  

The total timeout period is from a command is sent to the answer must be completely 
received. The total timeout period is 200 ms for the CMD_SIGN_ON command, 5 
seconds for the CMD_READ/PROGRAM_FLASH/EEPROM commands, and 1 
second for all other commands.