Programming Model
90
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Cortex
®
-M4F Processor
Table 1-9. PSR Register Field Descriptions (continued)
Bit
Field
Type
Reset
Description
15:10
ICI / IT
R
0h
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
for more
information.
The value of this field is only meaningful when accessing PSR or
EPSR.
9:8
RESERVED
R
0h
7:0
ISRNUM
R
0h
IPSR ISR Number. This field contains the exception type number of
the current Interrupt Service Routine (ISR). The value of this field is
only meaningful when accessing PSR or IPSR. 00h = Thread mode
01h = Reserved 02h = NMI 03h = Hard fault 04h = Memory
management fault 05h = Bus fault 06h = Usage fault 07h-0Ah =
Reserved 0Bh = SVCall 0Ch = Reserved for Debug 0Dh = Reserved
0Eh = PendSV 0Fh = SysTick 10h = Interrupt Vector 0 11h =
Interrupt Vector 1 ... ... 81h = Interrupt Vector 113