I creat a project use device (Intel)8xc251SA. there's error while compling since it need "c251.exe" to complier C file. I just find "cx51.exe" in keil directory. how can I solve this problem? is "Cx51 & 8051 development tools" can not suit for 8xc251 deivce? thanks for great help.....
You need the Keil C251 toolset for this device.
Look at the Products page: http://www.keil.com/product/default.asp You will see that the 8051 & 80251 tools are different Products!