SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 105

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

11.12.5.2
11.12.5.3
11.12.5.4
11.12.5.5
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
LDR
LDRSB
Operation
Restrictions
Condition flags
Examples
R0, LookUpTable
R7, localdata
Rt
Rt2
label
LDR loads a register with a value from a PC-relative memory address. The memory address is
specified by a label or by an offset from the PC.
The value to load or store can be a byte, halfword, or word. For load instructions, bytes and half-
words can either be signed or unsigned. See
label must be within a limited range of the current instruction.
offsets between label and the PC.
Table 11-19. Offset ranges
You might have to use the .W suffix to get the maximum offset range. See
selection” on page
In these instructions:
When Rt is PC in a word load instruction:
These instructions do not change the flags.
Instruction type
Word, halfword, signed halfword, byte, signed
byte
Two words
• Rt can be SP or PC only for word loads
• Rt2 must not be SP and must not be PC
• Rt must be different from Rt2.
• bit[0] of the loaded value must be 1 for correct execution, and a branch occurs to this
• if the instruction is conditional, it must be the last instruction in the IT block.
halfword-aligned address
; Load R0 with a word of data from an address
; labelled as LookUpTable
; Load a byte value from an address labelled
; as localdata, sign extend it to a word
; value, and put it in R7
is the register to load or store.
is the second register to load or store.
is a PC-relative expression. See
98.
“Address alignment” on page
Offset range
4095 to 4095
1020 to 1020
“PC-relative expressions” on page
Table 11-19
95.
shows the possible
SAM3X/A
SAM3X/A
“Instruction width
95.
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