Data file mode in 8085 Microprocessor

DATA FILE MODE in8085 Microprocessor

We can refer to ‘X8085 cross-assembler’ manual for details.

The format of Intel Hex: We have shown the MULT.HEX file to give a brief description at a glance.

:01 C100 00 04 3A

:01 C200 00 05 38

:02 C300 00 00 00 3B

:10 C000 00 21 00 C1 5E 16 00 21 00 C2 7E 21 00 00

FE 00 CA 90

:10 C010 00 17 C0 19 3D C2 12 C0 22 F7 FF 22 00

C3 CD BC 06 D3

:01 C020 00 76 A9

:00 0000 01 FF

There are several lines which the file consists of which are termed as records. We start the record with the character ‘:’. The record length of the field in hexadecimal is indicated by next two characters. In the last record, if the value is 00 it indicates EOF (end-of-file) record by 00. So it will be the last line of the file. Hence the next four characters are indicated by the load address field which is in hexadecimal. The next two characters are indicated by the field record type. For a data record it will be 00 and 01 stands for the end of the file record. In fact, for the program code which is stored as data record. So the last record for the field must be 01. After the type of the record field, excepting the last two characters, there are data Bytes. The check sum is formed by the last two characters which is generated as the complement of 2’s in the length of 8-bit addition for the length of field, address of the load field, type of the record field, and the data Bytes.

Let’s for example, in the fourth line of MULT.HEX there is:

:10 C000 00 21 00 C1 5E 16 00 21 00 C2 7E 21 00 00 FE 00 CA 90

We interpret the line as, 10 indicates there is 10H = 16 data Bytes in the given record. Starting from C000H records stored in the locations are indicated by C000. The type of record is Data record is indicated by 00. In hexadecimal the 16 data Bytes are 21, 00, C1, …, and CA. The check sum is 90 which is obtained as.

10 + C0 + 00 + 00 + 21 + 00 + C1 + … + CA = 70 with the carry of 5. If we Ignore the carry we get the result of the module. Hence the result of the addition of 8 bit modulo is 70H = 0111 0000B. The check sum of it is the 2's complement which is 1001 0000B = 90H.

In the following table different available options and its functionalities are depicted.