DSPIC30F2012 Microchip Technology Inc., DSPIC30F2012 Datasheet - Page 23

• Manufacturer Part Number: DSPIC30F2012
• Description: Dspic30f2011/2012/3012/3013 High-performance Digital Signal Controllers
• Manufacturer: Microchip Technology Inc.

2.4
The DSP engine consists of a high-speed 17-bit x
17-bit multiplier, a barrel shifter and a 40-bit adder/
subtracter (with two target accumulators, round and
saturation logic).
The DSP engine also has the capability to perform
inherent
which require no additional data. These instructions are
ADD, SUB and NEG.
The dsPIC30F is a single-cycle instruction flow archi-
tecture, therefore, concurrent operation of the DSP
engine with MCU instruction flow is not possible.
However, some MCU ALU and DSP engine resources
may be used concurrently by the same instruction (e.g.,
ED, EDAC). See Table 2-2.
TABLE 2-2:
© 2006 Microchip Technology Inc.
DSP Engine
Instruction
accumulator-to-accumulator
MOVSAC
MPY.N
EDAC
CLR
MAC
MAC
MPY
MSC
ED
DSP INSTRUCTION SUMMARY
dsPIC30F2011/2012/3012/3013
operations,
Algebraic Operation
A = 0
A = (x – y)
A = A + (x – y)
A = A + (x * y)
A = A + x
No change in A
A = x * y
A = – x * y
A = A – x * y
2
The DSP engine has various options selected through
various bits in the CPU Core Configuration register
(CORCON), as listed below:
1.
2.
3.
4.
5.
6.
7.
A block diagram of the DSP engine is shown in
Figure 2-2.
2
Note:
2
Fractional or integer DSP multiply (IF).
Signed or unsigned DSP multiply (US).
Conventional or convergent rounding (RND).
Automatic saturation on/off for ACCA (SATA).
Automatic saturation on/off for ACCB (SATB).
Automatic saturation on/off for writes to data
memory (SATDW).
Accumulator
(ACCSAT).
For CORCON layout, see Table 3-3.
Saturation
ACC WB?
mode
DS70139E-page 21
Yes
Yes
Yes
Yes
No
No
No
No
No
selection