2.7.2.1
Wake Up from WFI or Sleep-on-Exit
Normally, the processor wakes up only when the NVIC detects an exception with sufficient priority
to cause exception entry. Some embedded systems might have to execute system restore tasks
after the processor wakes up and before executing an interrupt handler. Entry to the interrupt handler
can be delayed by setting the
PRIMASK
bit and clearing the
FAULTMASK
bit. If an interrupt arrives
that is enabled and has a higher priority than current exception priority, the processor wakes up but
does not execute the interrupt handler until the processor clears
PRIMASK
. For more information
about
PRIMASK
and
FAULTMASK
2.7.2.2
Wake Up from WFE
The processor wakes up if it detects an exception with sufficient priority to cause exception entry.
In addition, if the
SEVONPEND
bit in the
SYSCTRL
register is set, any new pending interrupt triggers
an event and wakes up the processor, even if the interrupt is disabled or has insufficient priority to
cause exception entry. For more information about
SYSCTRL
, see page 173.
2.8
Instruction Set Summary
The processor implements a version of the Thumb instruction set. Table 2-13 on page 127 lists the
supported instructions.
Note:
■ Angle brackets, <>, enclose alternative forms of the operand
■ Braces, {}, enclose optional operands
■ The Operands column is not exhaustive
■
Op2
is a flexible second operand that can be either a register or a constant
■ Most instructions can use an optional condition code suffix
For more information on the instructions and operands, see the instruction descriptions in
the
ARM® Cortex™-M4 Technical Reference Manual
.
Table 2-13. Cortex-M4F Instruction Summary
Flags
Brief Description
Operands
Mnemonic
N,Z,C,V
Add with carry
{Rd,} Rn, Op2
ADC, ADCS
N,Z,C,V
Add
{Rd,} Rn, Op2
ADD, ADDS
-
Add
{Rd,} Rn , #imm12
ADD, ADDW
-
Load PC-relative address
Rd, label
ADR
N,Z,C
Logical AND
{Rd,} Rn, Op2
AND, ANDS
N,Z,C
Arithmetic shift right
Rd, Rm, <Rs|#n>
ASR, ASRS
-
Branch
label
B
-
Bit field clear
Rd, #lsb, #width
BFC
-
Bit field insert
Rd, Rn, #lsb, #width
BFI
N,Z,C
Bit clear
{Rd,} Rn, Op2
BIC, BICS
-
Breakpoint
#imm
BKPT
-
Branch with link
label
BL
-
Branch indirect with link
Rm
BLX
-
Branch indirect
Rm
BX
-
Compare and branch if non-zero
Rn, label
CBNZ
127
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller