EEPW论坛

Introduction The Binary Download Format (bdx) is a simple binary packet based file. BDX files are typically derived from a standard object module by converting the object module with the ‘convert’ utility program. The convert utility is supplied with all the vision tool products: visionClick, visionICE, visionPROBE, visionXD, and visionWARE. BDX files are intended for downloading into a target’s RAM memory via the vision tools. BDX Packet Format The format of the individual packets that make-up a bdx file consists of an eight byte header and up to a 20k byte data field. The packet format is as follows: 4bytes 2bytes 1byte 1byte 1...20k bytes Address Data Byte Count Data Sum Packet Number Data Field Address: The Address Field is a four-byte word that indicates where the data will be copied into the target system (most significant byte first). Data Byte Count: The Data Byte Count Field is a two-byte word that indicates the number of bytes contained in the Data Field portion of the packet (most significant byte first). Data Sum: The Data Sum field is a one-byte value and is a simple arithmetic sum of the bytes in the Data Field. This field is used to determine the basic packet integrity at the receiver. Packet Number: The Packet Number field consists of a one-byte word and indicates the current packet number. The packet number is used to detect dropped or missing packets at the receiver. The packet number ranges from 0x00 to 0xFF and rollovers if the number of packets exceeds 0xFF. Data Field: The Data Field can consist of up to 20k bytes of data. The number of bytes is specified in the Data Byte Count field.