Datasheet

© 2006 Microchip Technology Inc. Preliminary DS70178C-page 41
dsPIC30F1010/202X
4.0 ADDRESS GENERATOR UNITS
The dsPIC DSC core contains two independent
address generator units: the X AGU and Y AGU. The Y
AGU supports word sized data reads for the DSP MAC
class of instructions only. The dsPIC DSC AGUs
support three types of data addressing:
• Linear Addressing
• Modulo (Circular) Addressing
• Bit-Reversed Addressing
Linear and Modulo Data Addressing modes can be
applied to data space or program space. Bit-Reversed
Addressing is only applicable to data space addresses.
4.1 Instruction Addressing Modes
The Addressing modes in Table 4-1 form the basis of
the Addressing modes optimized to support the specific
features of individual instructions. The Addressing
modes provided in the MAC class of instructions are
somewhat different from those in the other instruction
types.
4.1.1 FILE REGISTER INSTRUCTIONS
Most file register instructions use a 13-bit address field
(f) to directly address data present in the first 8192
bytes of data memory (near data space). Most file
register instructions employ a working register, W0,
which is denoted as WREG in these instructions. The
destination is typically either the same file register, or
WREG (with the exception of the MUL instruction),
which writes the result to a register or register pair. The
MOV instruction allows additional flexibility and can
access the entire data space.
TABLE 4-1: FUNDAMENTAL ADDRESSING MODES SUPPORTED
Note: This data sheet summarizes features of this group
of dsPIC30F devices and is not intended to be a complete
reference source. For more information on the CPU,
peripherals, register descriptions and general device
functionality, refer to the “dsPIC30F Family Reference
Manual” (DS70046). For more information on the device
instruction set and programming, refer to the “dsPIC30F/
33F Programmer’s Reference Manual” (DS70157).
Addressing Mode Description
File Register Direct The address of the file register is specified explicitly.
Register Direct The contents of a register are accessed directly.
Register Indirect The contents of Wn forms the EA.
Register Indirect Post-modified The contents of Wn forms the EA. Wn is post-modified (incremented or
decremented) by a constant value.
Register Indirect Pre-modified Wn is pre-modified (incremented or decremented) by a signed constant value
to form the EA.
Register Indirect with Register Offset The sum of Wn and Wb forms the EA.
Register Indirect with Literal Offset The sum of Wn and a literal forms the EA.