2: Programmer’s Model
ARM720T CORE CPU MANUAL EPSON 2-17
2.11 Implementation-defined behavior of instructions
The
ARM Architecture Reference Manual
defines the instruction set of the ARM720T
processor:
• See
Indexed addressing on a Data Abort
for the behavior of instructions that are
identified as implementation-defined in the
ARM Architecture Reference Manual
.
• See
Early termination
for those features that define signed and unsigned early
termination on the ARM720T processor.
2.11.1 Indexed addressing on a Data Abort
In the event of a Data Abort with pre-indexed or post-indexed addressing, the value left in Rn
is defined to be the updated base register value for the following instructions:
•LDC
•LDM
•LDR
•LDRB
• LDRBT
•LDRH
•LDRSB
•LDRSH
•LDRT
•STC
•STM
•STR
•STRB
•STRBT
•STRH
• STRT.
2.11.2 Early termination
On the ARM720T, early termination is defined as:
MLA, MUL Signed early termination.
SMULL, SMLAL Signed early termination.
UMULL, UMLAL Unsigned early termination.
