Region 1
Disabled subregion
Disabled subregion
Region 2, with
subregions
Base address of both regions
Offset from
base address
0
64KB
128KB
192KB
256KB
320KB
384KB
448KB
512KB
Functional Peripherals Description
88
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Cortex-M4F Peripherals
Example of SRD Use
Two regions with the same base address overlap. Region one is 128 KB, and region two is 512 KB. To
ensure the attributes from region one apply to the first 128 KB region, configure the SRD field for region
two to 0x03 to disable the first two subregions, as
shows.
Figure 2-1. SRD Use Example
2.2.4.3
MPU Mismatch
When an access violates the MPU permissions, the processor generates a memory management fault
(see
for more information). The MMFSR register indicates the cause of the fault.
2.2.5 Floating-Point Unit (FPU)
This section describes the Floating-Point Unit (FPU) and the registers it uses. The FPU provides:
•
32-bit instructions for single-precision (C float) data-processing operations
•
Combined multiply and accumulate instructions for increased precision (Fused MAC)
•
Hardware support for conversion, addition, subtraction, multiplication with optional accumulate,
division, and square root
•
Hardware support for denormals and all IEEE rounding modes
•
32 dedicated 32-bit single-precision registers, also addressable as 16 double-word registers
•
Decoupled three stage pipeline
The Cortex-M4F FPU fully supports single-precision add, subtract, multiply, divide, multiply and
accumulate, and square root operations. It also provides conversions between fixed-point and floating-
point data formats, and floating-point constant instructions. The FPU provides floating-point computation
functionality that is compliant with the ANSI/IEEE Std 754-2008, IEEE Standard for Binary Floating-Point
Arithmetic, referred to as the IEEE 754 standard. The FPU's single-precision extension registers can also
be accessed as 16 double-word registers for load, store, and move operations.
2.2.5.1
FPU Views of the Register Bank
The FPU provides an extension register file containing 32 single-precision registers. These can be viewed
as:
•
Sixteen 64-bit double-word registers, D0-D15
•
Thirty-two 32-bit single-word registers, S0-S31
•
A combination of registers from the above views