Indicate to the assembler the start of a data section.
[Syntax]
Symbol field
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Mnemonic field
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Operand field
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Comment field
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[section-name]
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.DSEG
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[relocation-attribute]
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[; comment]
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[Function]
- | The .DSEG directive indicates to the assembler the start of a data section. |
- | A memory following the .DSEG directive belongs to the data section until it comes across a section definition directives. |
[Description]
- | This directive defines a portion that defines data in a program.
This directive is valid until another section definition directive appears. |
- | DSEG directive can specify the start address of a section by specifying DATA_AT nad BSS_AT in the operand field.
The section start address can also be specified through the .ORG directive.
In this case, the section name will be "the specified section name" + "_AT" + "specified address (hexadecimal notation in uppercase letters without prefix (0x or 0X) or suffix (h or H)". |
- | The following shows the relocation attributes that can be specified through .DSEG. |
Table 5.17 | Relocation Attributes of .DSEG |
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SDATA
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SDATA
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.sdata
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Allocates a section for data having initial values in the saddr areaNote 2 with the start address set to an even address.
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2
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SBSS
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SBSS
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.sbss
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Allocates a section for data having no initial values in the saddr areaNote 2 with the start address set to an even address.
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2
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DATA
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DATA
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.data
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Allocates a section for data having initial values between addresses 0xF0000 and 0xFFFFF in the RAM areaNote 2 with the start address set to an even address so that it does not extend across a boundary of 64 Kbytes - 1Note 3.
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2
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BSS
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BSS
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.bss
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Allocates a section for data having no initial values between addresses 0xF0000 and 0xFFFFF in the RAM areaNote 2 with the start address set to an even address so that it does not extend across a boundary of 64 Kbytes - 1Note 3.
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2
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DATAF
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DATAF
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.dataf
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Allocates a section for data having initial values with the start address set to an even address so that it does not extend across a boundary of 64 Kbytes - 1Note 3.
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2
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BSSF
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BSSF
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.bssf
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Allocates a section for data having no initial values with the start address set to an even address so that it does not extend across a boundary of 64 Kbytes - 1Note 3.
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2
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DATA_ATΔaddress
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DATA_AT absolute- expressionNote 4
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None
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Allocates a section for data having initial values at a specified address.
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1 (fixed)
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BSS_ATΔaddress
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BSS_AT absolute- expressionNote 4
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None
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Allocates a section for data having no initial values at a specified address.
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1 (fixed)
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Note 1. | The alignment condition can be modified through the .ALIGN directive. |
Note 2. | For the code flash area, mirror area, RAM area, and saddr area, see the user's manual of the device. For the RAM area, note that only the on-chip RAM allocated to an address range from 0xF0000 to 0xFFFFF is supported. |
Note 3. | Allocation beyond a boundary of 64 Kbytes - 1 is prohibited by default. |
Note 4. | If the specified absolute expression is illegal or its value is outside the range from 0x00000 to 0xFFFFF, an error will occur. |
- | A directive that specifies initial values cannot be written in a section definition for data having no initial values. If described, an error is output. |
- | When a section definition does not include a section name, the assembler gives a separate default section name for each relocation attribute.
The following shows the section names given by the assembler |
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SDATA
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.sdata
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SBSS
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.sbss
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DATA
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.data
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BSS
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.bss
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DATAF
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.dataf
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BSSF
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.bssf
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DATA_ATΔaddress
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.data_AT start-address
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BSS_ATΔaddress
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.bss_AT start-address
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A section having one of the above names has the corresponding relocation attribute shown above and no different relocation attribute can be assigned.
- | When a section definition does not include a relocation attribute, relocation attribute "DATA" is assumed. |
- | The following characters are usable in section names. |
- | Alphanumeric characters (0-9, a-z, A-Z) |
- | Special characters (@, _, .) |
[Example]
To define section ".data" having the DATA attribute.
To define section "_S" having the SDATA attribute.
To define section "EX" having the DATA_AT attribute with address 0xff000 specified.
The section name will be set to "EX_ATFF000".
EX .DSEG DATA_AT 0xff000
.DS 2
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