EFM32-TG-STK3300 Energy Micro, EFM32-TG-STK3300 Datasheet - Page 77

• Manufacturer Part Number: EFM32-TG-STK3300
• Description: MCU, MPU & DSP Development Tools TG Starter Kit
• Manufacturer: Energy Micro
• Series: EFM®32r
• Type: MCUr

Specifications of EFM32-TG-STK3300

• Processor To Be Evaluated: EFM32
• Processor Series: EMF32 Tiny Gecko
• Data Bus Width: 32 bit
• Interface Type: USB, JTAG, LCD, Touch Interface
• Operating Supply Voltage: 5 V
• Contents: Board, Cable, CD and Documentation
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: EFM32-TGXXX

3.9.3.2 Operation
3.9.3.3 Restrictions
3.9.3.4 Condition flags
3.9.3.5 Example
2011-02-04 - d0002_Rev1.00
The IT instruction makes up to four following instructions conditional. The conditions can be all the
same, or some of them can be the logical inverse of the others. The conditional instructions following
the IT instruction form the IT block.
The instructions in the IT block, including any branches, must specify the condition in the {cond} part
of their syntax.
Note
A BKPT instruction in an IT block is always executed, even if its condition fails.
Exceptions can be taken between an IT instruction and the corresponding IT block, or within an IT block.
Such an exception results in entry to the appropriate exception handler, with suitable return information
in LR and stacked PSR.
Instructions designed for use for exception returns can be used as normal to return from the exception,
and execution of the IT block resumes correctly. This is the only way that a PC#modifying instruction is
permitted to branch to an instruction in an IT block.
The following instructions are not permitted in an IT block:
• IT
• CBZ and CBNZ
• CPSID and CPSIE.
Other restrictions when using an IT block are:
• a branch or any instruction that modifies the PC must either be outside an IT block or must be the
• do not branch to any instruction inside an IT block, except when returning from an exception handler
• all conditional instructions except Bcond must be inside an IT block. Bcond can be either outside or
• each instruction inside the IT block must specify a condition code suffix that is either the same or
Note
This instruction does not change the flags.
last instruction inside the IT block. These are:
• ADD PC, PC, Rm
• MOV PC, Rm
• B, BL, BX, BLX
• any LDM, LDR, or POP instruction that writes to the PC
• TBB and TBH
inside an IT block but has a larger branch range if it is inside one
logical inverse as for the other instructions in the block.
Your assembler might be able to generate the required IT instructions for conditional
instructions automatically, so that you do not need to write them yourself. See your
assembler documentation for details.
Your assembler might place extra restrictions on the use of IT blocks, such as prohibiting
the use of assembler directives within them.
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