The Intel object format supports 16-bit addresses and 32-bit extended addresses. Intel format consists of a 9-character (4-field) prefix (which defines the start of record, byte count, load address, and record type), the data, and a 2-character checksum suffix.
The 9-character prefix represents three record types:
| Record Type | Description |
|---|---|
| 00 | Data record |
| 01 | End-of-file record |
| 04 | Extended linear address record |
Record type00, the data record, begins with a colon ( : ) and is followed by the byte count, the address of the first data byte, the record type (00), and the checksum. The address is the least significant 16 bits of a 32-bit address; this value is concatenated with the value from the most recent 04 (extended linear address) record to create a full 32-bit address. The checksum is the 2s complement (in binary form) of the preceding bytes in the record, including byte count, address, and data bytes.
Record type 01, the end-of-file record, also begins with a colon ( : ), followed by the byte count, the address, the record type (01), and the checksum.
Record type 04, the extended linear address record, specifies the upper 16 address bits. It begins with a colon ( : ), followed by the byte count, a dummy address of 0h, the record type (04), the most significant 16 bits of the address, and the checksum. The subsequent address fields in the data records contain the least significant bytes of the address.
Figure 12-7 illustrates the Intel hexadecimal object format.