Microchip Technology MA330028 Data Sheet
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X AND PIC24EPXXXGP/MC20X
DS70000657H-page 62
2011-2013 Microchip Technology Inc.
4.2.5
X AND Y DATA SPACES
The dsPIC33EPXXXMC20X/50X and
dsPIC33EPXXXGP50X core has two Data Spaces,
X and Y. These Data Spaces can be considered either
separate (for some DSP instructions) or as one unified
linear address range (for MCU instructions). The Data
Spaces are accessed using two Address Generation
Units (AGUs) and separate data paths. This feature
allows certain instructions to concurrently fetch two
words from RAM, thereby enabling efficient execution
of DSP algorithms, such as Finite Impulse Response
(FIR) filtering and Fast Fourier Transform (FFT).
The X Data Space is used by all instructions and
supports all addressing modes. X Data Space has
separate read and write data buses. The X read data
bus is the read data path for all instructions that view
Data Space as combined X and Y address space. It is
also the X data prefetch path for the dual operand DSP
instructions (MAC class).
The Y Data Space is used in concert with the X Data
Space by the MAC class of instructions (CLR, ED,
EDAC
dsPIC33EPXXXGP50X core has two Data Spaces,
X and Y. These Data Spaces can be considered either
separate (for some DSP instructions) or as one unified
linear address range (for MCU instructions). The Data
Spaces are accessed using two Address Generation
Units (AGUs) and separate data paths. This feature
allows certain instructions to concurrently fetch two
words from RAM, thereby enabling efficient execution
of DSP algorithms, such as Finite Impulse Response
(FIR) filtering and Fast Fourier Transform (FFT).
The X Data Space is used by all instructions and
supports all addressing modes. X Data Space has
separate read and write data buses. The X read data
bus is the read data path for all instructions that view
Data Space as combined X and Y address space. It is
also the X data prefetch path for the dual operand DSP
instructions (MAC class).
The Y Data Space is used in concert with the X Data
Space by the MAC class of instructions (CLR, ED,
EDAC
, MAC, MOVSAC, MPY, MPY.N and MSC) to provide
two concurrent data read paths.
Both the X and Y Data Spaces support Modulo
Addressing mode for all instructions, subject to
addressing mode restrictions. Bit-Reversed Addressing
mode is only supported for writes to X Data Space.
Modulo Addressing and Bit-Reversed Addressing are
not present in PIC24EPXXXGP/MC20X devices.
All data memory writes, including in DSP instructions,
view Data Space as combined X and Y address space.
The boundary between the X and Y Data Spaces is
device-dependent and is not user-programmable.
Both the X and Y Data Spaces support Modulo
Addressing mode for all instructions, subject to
addressing mode restrictions. Bit-Reversed Addressing
mode is only supported for writes to X Data Space.
Modulo Addressing and Bit-Reversed Addressing are
not present in PIC24EPXXXGP/MC20X devices.
All data memory writes, including in DSP instructions,
view Data Space as combined X and Y address space.
The boundary between the X and Y Data Spaces is
device-dependent and is not user-programmable.
4.3
Memory Resources
Many useful resources are provided on the main prod-
uct page of the Microchip web site for the devices listed
in this data sheet. This product page, which can be
accessed using this
uct page of the Microchip web site for the devices listed
in this data sheet. This product page, which can be
accessed using this
, contains the latest updates
and additional information.
4.3.1
KEY RESOURCES
• “Program Memory” (DS70613) in the “dsPIC33/
PIC24 Family Reference Manual”
• Code Samples
• Application Notes
• Software Libraries
• Webinars
• All Related “dsPIC33/PIC24 Family Reference
• Application Notes
• Software Libraries
• Webinars
• All Related “dsPIC33/PIC24 Family Reference
Manual”
Sections
• Development Tools
Note:
In the event you are not able to access the
product page using the link above, enter
this URL in your browser:
product page using the link above, enter
this URL in your browser: