Description
Reset
Type
Name
Bit/Field
EPSR
ICI / IT status
These bits, along with bits 26:25, contain the Interruptible-Continuable
Instruction (
ICI
) field for an interrupted load multiple or store multiple
instruction or the execution state bits of the
IT
instruction.
When an interrupt occurs during the execution of an
LDM
,
STM
,
PUSH
POP
,
VLDM
,
VSTM
,
VPUSH
, or
VPOP
instruction, the processor stops the
load multiple or store multiple instruction operation temporarily and
stores the next register operand in the multiple operation to bits 15:12.
After servicing the interrupt, the processor returns to the register pointed
to by bits 15:12 and resumes execution of the multiple load or store
instruction. When
EPSR
holds the
ICI
execution state, bits 11:10 are
zero.
The If-Then block contains up to four instructions following a 16-bit
IT
instruction. Each instruction in the block is conditional. The conditions
for the instructions are either all the same, or some can be the inverse
of others. See the Cortex™-M4 instruction set chapter in the
ARM®
Cortex™-M4 Devices Generic User Guide (literature number
)
for more information.
The value of this field is only meaningful when accessing
PSR
or
EPSR
.
0x0
RO
ICI / IT
15:10
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0
RO
reserved
9:8
IPSR
ISR Number
This field contains the exception type number of the current Interrupt
Service Routine (ISR).
Description
Value
Thread mode
0x00
Reserved
0x01
NMI
0x02
Hard fault
0x03
Memory management fault
0x04
Bus fault
0x05
Usage fault
0x06
Reserved
0x07-0x0A
SVCall
0x0B
Reserved for Debug
0x0C
Reserved
0x0D
PendSV
0x0E
SysTick
0x0F
Interrupt Vector 0
0x10
Interrupt Vector 1
0x11
...
...
Interrupt Vector 113
0x81
See “Exception Types” on page 114 for more information.
The value of this field is only meaningful when accessing
PSR
or
IPSR
.
0x00
RO
ISRNUM
7:0
95
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller