Epson S5U1C63000A Computer Accessories User Manual


 
CHAPTER 4: ASSEMBLER
76 EPSON S5U1C63000A MANUAL
(S1C63 FAMILY ASSEMBLER PACKAGE)
.align pseudo-instruction
Instruction format
.align <Alignment number>
<Alignment number>:
Word alignment in 2
n
value
• Only decimal, binary and hexadecimal numbers can be described.
• The alignment that can be specified is a 2
n
value.
• One or more spaces or tabs are necessary between the instruction and the alignment number.
Sample description:
.code
.align 32 ... Sets the location to the next 32-word boundary address.
Function
Specifies location alignment in words of a CODE, DATA or BSS section in an assembly source file. The
section with the .align pseudo-instruction can be taken as a loosely absolute section in the sense that
its location is partially defined.
Precautions
When the .align pseudo-instruction appears in a section, a new absolute section starts at that point.
The section type does not change. The .align pseudo-instruction keeps its effect only in that section
until the next section definer (.code, .data or .bss) or the next location definer (.org or .align) appears.
Example:
:
.code ... The latest relocatable section definition.
:
.align 32 ... Starts new loosely absolute CODE section from the next 32-word boundary address.
:
.bss ... This section is relocatable not affected by the ".align" pseudo-instruction.
:
.code ... This section is also relocatable not affected by the ".align" pseudo-instruction.
:
If the .align pseudo-instruction is defined immediately after a section definer (.code, .data or .bss), the
section definer does not start a new section. But .align starts a new section with the attribute of the
section definer.
Example:
.code ... This does not start a new CODE section.
.align 32 ... This starts a loosely absolute CODE section.
:
If the .align pseudo-instruction is defined immediately before a section definer (.code, .data or .bss), it
does not start a new section and makes no effect to the following sections.
Example:
.code ... The latest relocatable section definition.
:
.align 32 ... This does not start a new absolute section and makes no effect.
.bss ... The another kind (BSS) of section which is not affected by the
: previous ".align" pseudo-instruction in the CODE section.
.code ... This will be an relocatable CODE section not affected by the
: previous ".align" pseudo-instruction.