dsPIC30F3014/4013
3.2 Data Address Space
The core has two data spaces. The data spaces can be
considered either separate (for some DSP instruc-
tions), 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.
3.2.1 DATA SPACE MEMORY MAP
The data space memory is split into two blocks, X and
Y data space. A key element of this architecture is that
Y space is a subset of X space, and is fully contained
within X space. In order to provide an apparent Linear
Addressing space, X and Y spaces have contiguous
addresses.
When executing any instruction other than one of the
MAC class of instructions, the X block consists of the 64-
Kbyte data address space (including all Y addresses).
When executing one of the MAC class of instructions,
the X block consists of the 64-Kbyte data address
space excluding the Y address block (for data reads
only). In other words, all other instructions regard the
entire data memory as one composite address space.
The MAC class instructions extract the Y address space
from data space and address it using EAs sourced from
W10 and W11. The remaining X data space is
addressed using W8 and W9. Both address spaces are
concurrently accessed only with the MAC class
instructions.
The data space memory map is shown in Figure 3-7.
DS70138E-page 28
© 2007 Microchip Technology Inc.