Note the following details of the code protection feature on Microchip devices:
•Microchip products meet the specification contained in their particular Microchip Data Sheet.
•Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•Microchip is willing to work with the customer who is concerned about the integrity of their code.
•Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digit al Millennium Copyright Act. If suc h a c t s
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
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and may be su perseded by upda t es . It is y our responsibility to
ensure that your application meets with your specifications.
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EELOQ, microID, MPLAB, PIC, PIC, PICSTART,
PROMATE, PowerSmart, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
AmpLab, FilterLab, MigratableMemory,MXDEV,MXLAB,SEEVAL, SmartSensor and The Embedded Control SolutionsCompany are registered trademarks of Microchip TechnologyIncorporated in the U.S.A.
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Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. TheCompany’s quality systemprocesses and procedures are forits PIC8-bit MCUs, KEELOQmicroperipherals, nonvolatilememory and analogproducts. In addition,Microchip’s quality system for the design and manufactureof development systems is ISO 9001:2000 certified.
Note: This data sheet summarizes features of this g roup
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 ReferenceManual” (DS70046). For more informat ion on the device
instruction set and programming, refer to the “dsPIC30F/33F Programmer’s Reference Manual” (DS70157).
High-Performance Modified RISC CPU:
• Modified Harvard architecture
• C compiler optimized instruction set architecture
• Flexible addressing modes
• 83 base instructions
• 24-bit wide instructions, 16-bit wide data path
• Up to 24 Kbytes on-chip Flash program space
• Up to 2 Kbytes of on-chip data RAM
• Up to 1 Kbytes of nonvolatile data EEPROM
• 16 x 16-bit working register array
• Up to 30 MIPS operation:
- DC to 40 MHz external clock input
- 4 MHz - 10 MHz oscillator input with
PLL active (4x, 8x, 16x)
• Up to 21 interrupt sources:
- 8 user-selectable priority levels
- 3 external interrupt sources
- 4 proce ssor trap sources
DSP Features:
• Dual data fetch
• Modulo and Bit-Reversed modes
• Two 40-bit wide accumulators with optional
saturation logic
• 17-bit x 17-bit single-cycle hardw are frac tio nal /
integer multiplier
• All DSP instructions are single cycle
- Multiply-Accumulate (MAC) operation
• single-cycle ±16 shift
Peripheral Features:
• High-current sink/source I/O pins: 25 mA/25mA
• Three 16-bit timers/counters; optionally pair up
16-bit timers into 32-bit timer modules
• 16-bit Capture input functions
• 16-bit Compare/PWM output functions
• 3-wire SPI modules (supports four Frame modes)
2
•I
C™ module supports Multi-Master/Slave mode
and 7-bit/10-bit addressing
• Up to two addressable UART modules with FIFO
buffers
17.0 System Integration................................... ................................................................................................................................119
18.0 Instruction Set Summary..........................................................................................................................................................133
19.0 Development Support............................................................................................................................................................... 141
Index ..................................................................................................................................................................................................193
The Microchip Web Site..................................................................................................................................................................... 199
Customer Change Notification Service ..............................................................................................................................................199
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
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welcome your feedback.
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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 ReferenceManual” (DS70046). For more informat ion on the device
instruction set and programming, refer to the “dsPIC30F/33F Programmer’s Reference Manual“ (DS70157).
This data sheet contains information specific to the
dsPIC30F2011, dsPIC30F2012, dsPIC30F3012 and
dsPIC30F3013 Digit al Signal Controll ers (DSC). These
devices contain extensive Digital Signal Processor
(DSP) functionality within a high-performance 16-bit
microcontroller (MCU) architecture.
The following block di agrams depict the archi tecture for
these devices:
• Figure 1-1 illustrates the dsPIC30F2011
• Figure 1-2 illustrates the dsPIC30F2012
• Figure 1-3 illustrates the dsPIC30F3012
• Figure 1-4 illustrates the dsPIC30F3013
Following the block d iag ram s, Table 1-1 relates the I/O
Table 1-1 provides a brief description of device I/O
pinouts and the functions that may be multiplexed to a
port pin. Multiple functions may exist on one port pin.
When multiplexing occurs, the peripheral module’s
functional requirements may force an override of the
data direction of the port pin.
TABLE 1-1:PINOUT I/O DESCRIPTIONS
Pin Name
AN0 - AN9IAnalogAnalog input channels.
AV
DDPPPositive supply for analog module.
SSPPGround reference fo r an al og module.
AV
CLKI
CLKO
CN0 - CN7ISTInput ch ange notification inputs.
EMUD
EMUC
EMUD1
EMUC1
EMUD2
EMUC2
EMUD3
EMUC3
IC1 - IC2ISTCapture in puts 1 thr ou gh 2.
INT0
INT1
INT2
LVDINIAnalogLow-Voltage Detect Reference Voltage Input pin.
MCLR
OC1-OC2
OCFA
OSC1
OSC2
PGD
PGC
RB0 - RB9I/OSTPORTB is a bidirectional I/O port.
RC13 - RC15I/OSTPORTC is a bidirectional I/O port.
RD0, RD8 - RD9I/OSTPORTD is a bidirectional I/O port.
RF2 - RF5I/OSTPORTF is a bidirectional I/O port.
SCK1
SDI1
SDO1
1
SS
Pin
Type
I
O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I
I
I
I/PSTMaste r Cl ear (Reset) input or programm i ng voltage input. This
O
I
I
I/O
I/O
I
I/O
I
O
I
Legend: CMOS =CMOS compatible input or out put Analog =Analog input
ST=Schmitt Trigger input with CMOS levels O=Output
I=Input P=Power
Buffer
Type
ST/CMOS—External clock source i nput. Alway s associated with OSC1 pin
function.
Oscillator crystal outp ut . Co nnects to crystal or resonator in
Crystal Oscillator mode. Optionally functions as CLKO in RC
and EC modes. Always ass ociated with OSC2 pin function.
Can be software programmed for internal weak pull-ups on all
inputs.
ST
ST
ST
ST
ST
ST
ST
ST
ST
ST
ST
—
ST
ST/CMOS—Oscillator crystal input. ST buffer when configured in RC mode;
ST
ST
ST
ST
—
ST
ICD Primary Communi cation Channel data input/ou tp ut pi n.
ICD Primary Communication Channel clock input/output pin.
ICD Secondary Communication Channel data input/output pin.
ICD Secondary Comm unication Channel cloc k i nput/output pin.
ICD T ertiary Communication Channel data input/output pin.
ICD Tertiary Communication Channel clock input/output pin.
ICD Quaternary Comm unication Channel data input /o utput pin.
ICD Quaternary Comm unication Channel clock in put / ou tp ut pi n.
pin is an active-low Reset to the device.
Compare outputs 1 through 2.
Compare Fault A input.
CMOS otherwise.
Oscillator crystal outp ut . Co nnects to crystal or resonator in
Crystal Oscillator mode. Optionally functions as CLKO in RC
and EC modes.
In-Circuit Serial Programmi ng™ data input/output pin.
In-Circuit Serial Programmi ng clock input pin.
Synchronous serial clock input/output for SPI1.
SPI1 Data In.
SPI1 Data Out.
SPI1 Slave Synchronization.
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 ReferenceManual” (DS70046). For more informat ion on the device
instruction set and programming, refer to the “dsPIC30F/33F Programmer’s Reference Manual” (DS70157).
This section is an overview of the CPU architecture of
the dsPIC30F. The core has a 24-bit instruction word.
The Program Counter (PC) is 23 bits wide with the
Least Significant bit (LSb) always clear (see
Section 3.1 “Program Address Space”). The Most
Significant bit (MSb) is ignored during normal program
execution, except for certain specialized instructions.
Thus, the PC can address up to 4M instruction words
of user program spac e. An instruction prefetch m e ch anism helps maintain throughput. Program loop constructs, free from loop count management overhead,
are supported using the DO and REPEAT instructions,
both of which are interruptible at any point.
2.1Core Overview
The working registe r array consis ts of 16 x 16-bit re gisters, each of which can act as data, address or offset
registers. One working register (W15) operates as a
Software Stack Pointer for interrupts and calls.
The data space is 64 Kbytes (32K words) and is split
into two blocks, referred to as X and Y data memory.
Each block has its own independent Address Generation Unit (AGU). Most instructions operate solely
through the X memory, AGU, which provides the
appearance of a single unified data space. The
Multiply-Accu mulate (MAC) class of dual s ource DSP
instructions operate through both the X and Y AGUs,
splitting the data address space into two parts (see
Section 3.2 “Data Address Space”). The X and Y
data space boundary is device specific and cannot be
altered by the user. Each data word consists of 2 bytes
and most instruction s can address da ta either as words
or bytes.
Two ways to access data in program memory are:
• The upper 32 Kbytes of data space memory can
be mapped into the lower half (user space) of
program space at any 16K program word boundary, defined by the 8-bit Program Space Visibility
Page (PSVPAG) register. Thus any instruction
can access program space as if it were data
space, with a limitation that the access requires
an additional cycle. On ly the low er 16 bit s of ea ch
instruction word can be accessed using this
method.
• Linear indirect access of 32K word pages within
program space is als o possibl e using any work ing
register, via table read and write instructions.
Table read and write instructions can be used to
access all 24 bits of an instruction word.
Overhead-free circular buffers (Modulo Addressing)
are supported in both X and Y address spaces. This is
primarily intended to remove the loop overhead for
DSP algorithms.
The X AGU also support s Bit-Reverse d Addressi ng on
destination ef fective addresses to great ly simplify input
or output data reordering for radix-2 FFT algorithms.
Refer to Section 4.0 “Address Generator Units” for
details on Modulo and Bit-Reversed Addressing.
The core supports Inherent (no operand), Relative,
Literal, Memory Direct, Register Direct, Register
Indirect, Register Offset and Literal Offset Addressing
modes. Instructions are associated with pre-defined
addressing modes, depending upon their functional
requirements.
For most i ns tru c ti o ns , the c or e i s c apa bl e of e xe c ut i ng
a data (or program data) memory read, a working register (data) read, a data memory write and a program
(instruction) memory read per instruction cycle. As a
result, 3 operand instructions are supported, allowing
C = A+B operations to be executed in a single cycle.
A DSP engine has been included to significantly
enhance the core arithmetic capability and throughput.
It features a high-speed 17-bit by 17-bit multiplier, a
40-bit ALU, two 40-bit saturating accumulators and a
40-bit bidirectional b arre l s hi fter. Data in the accumulator or any wor kin g regi ste r can be sh ifted up to 15 bi ts
right, or 16 bits left in a single cycle. The DSP instructions operate seamles sly with all other in struct ion s and
have been desi gned for o ptimal re al-time p erformanc e.
The MAC class of instructions can concurrently fetch
two data operands from memory while multiplying two
W registers. To enable this concurrent fetching of data
operands, the data space has been split for these
instructions and linear is for all others. This has been
achieved in a transpar en t and fle xib le mann er, by dedicating certai n working registe rs to eac h address spac e
for the MAC class of instructions.
The core does not support a multi-stage instruction
pipeline. However, a single-stage instruction prefetch
mechanism is used, which accesses and partially
decodes instructions a cycle ahead of execution, in
order to maximize available execution time. Most
instructions execute in a single cycle with certain
exceptions.
The core features a vectored exception processing
structure for traps and interrupts, with 62 independent
vectors. The exceptions consist of up to 8 traps (of
which 4 are reserved) a nd 54 int errup ts. Each interrupt
is prioritized based on a us er-assigned priori ty between
1 and 7 (1 being the lowest priority and 7 being the
highest), in conjunction with a predetermined ‘natural
order’. Traps have fixed priorities ranging from 8 to 15.
2.2Programmer’s Model
The programmer’s model is shown in Figure 2-1 and
consists of 16 x 16-bit working registers (W0 through
W15), 2 x 40-bit accumulators (ACCA and ACCB),
STATUS register (SR), Data Table Page register
(TBLPAG), Program Space Visibility Page register
(PSVPAG), DO and REPEAT registers (DOSTART,
DOEND, DCOUNT and RCOUNT) and Program
Counter (PC). The working registers can act as data,
address or offset registers. All registers are memory
mapped. W0 acts as the W register for file register
addressing.
Some of these registers have a shadow register associated with each of them, as shown in Figure 2-1. The
shadow register is used as a temp orary holding reg ister
and can transfer it s con ten ts to or from its host reg is ter
upon the occurrence of an event. None of the shadow
registers are accessible directly. The following rules
apply for transfer of registers into and out of shadows.
• PUSH.S and POP.S
W0, W1, W2, W3, SR (DC, N, OV, Z and C bits
only) are transferred.
• DO instruction
DOSTART, DOEND, DCOUNT shadows are
pushed on loop start and popped on loop end.
When a byte operation is performed on a working register , only th e Least Significan t Byte (LSB) of th e targ et
register is affected. However, a benefit of memory
mapped working registers is that both the Least and
Most Significant Bytes (MSB) can be manipulated
through byte-wide data memory space accesses.
2.2.1SOFTWARE STACK POINTER/
FRAME POINTER
The dsPIC® DSC devices contain a software stack.
W15 is the dedicated Software Stack Pointer (SP),
which is autom atical ly modifi ed by exce ption pr ocessing and subroutine calls and returns. However, W15
can be referenced by any instruction in the same manner as all other W register s. This simpli fies the read ing,
writing and mani pulati on of the Stack Pointe r (e.g., cr eating stack frames).
Note:In order to protect against misaligned
stack accesses, W15<0> is always clear.
W15 is initialized to 0x0800 during a Reset. The user
may reprogram the SP during initialization to any
location within data space.
W14 has been dedica ted as a Stack Frame Po int er, as
defined by the LNK and ULNK instructions. However,
W14 can be referenced by any instruction in the same
manner as all other W registers.
2.2.2STATUS REGISTER
The dsPIC DSC core has a 16-bit STATUS register
(SR), the LSB of which is referred to as the SR Low
byte (SRL) and the MSB as the SR High byte (SRH).
See Figure 2-1 for SR layout.
SRL contains all the MCU ALU operation Status flags
(including the Z bit), as wel l as the CPU Inter rupt Pri ority Level Status bits, IPL<2:0>, and the Repeat Active
Status bit, RA. During exception processing, SRL is
concatenated with the MSB of the PC to form a complete word value which is then stacked.
The upper byte of the STATUS register contains the
DSP Adder/Subtracter Status bits, the DO Loop Active
bit (DA) and the Digit Carry (DC) Status bit.
2.2.3PROGRAM COUNTER
The program counter is 23 bits wide; bit 0 is always
clear. Therefore, the PC can address up to 4M
instruction words.
The dsPIC DSC devices feature a 16/16-bit signed
fractional divide ope rati on , as w ell as 32/16-bit and 16/
16-bit signed an d unsigned intege r divide operati ons, in
the form of single instruction iterative divides. The following instructions and data sizes are supported:
1.DIVF - 16/16 signed fractional divide
2.DIV.sd - 32/16 signed divide
3.DIV.ud - 32/16 unsigned divide
4.DIV.s - 16/16 signed divide
5.DIV.u - 16/16 unsigned divide
The 16/16 divides are similar to the 32/16 (same number
of iterations), but the dividend is either zero-extended or
sign-extended during the first iteration.
The divide instructions must be executed within a
REPEAT loop. Any other form of execution (e.g., a
series of discrete divide instructions) will not function
correctly because the instruction flow depends on
RCOUNT . Th e divide instructi on does not automatica lly
set up the RCOUNT value and it must, therefore, be
explicitly and correctl y specifi ed in the REPEAT instruction, as shown in Table 2-1 (REPEAT executes the target instruction {operand value+1} times). The REPEAT
loop count must be setup for 18 iterations of the DIV/DIVF instruction. Thus, a complete divide operation
requires 19 cycles.
Note:The divide flow is interruptible. However,
TABLE 2-1:DIVIDE INSTRUCTIONS
InstructionFunction
DIVF
DIV.sdSigned divide: (Wm+1:Wm)/Wn → W0; Rem → W1
DIV.sSigned divide: Wm/Wn → W0; Rem → W1
DIV.udUnsigned divide: (Wm+1:Wm)/Wn → W0; Rem → W1
DIV.uUnsigned divide: Wm/Wn → W0; Rem → W1
Signed fractional divide: Wm/Wn → W0; Rem → W1
the user needs to save the context as
appropriate.
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 accumulator-to-accumulator operations,
which require no ad ditional dat a. These instr uctions are
ADD, SUB and NEG.
The dsPIC30F is a single-cycle instruction flow architecture, 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 concu rrently by the s ame instruction (e.g.,
ED, EDAC). See Table 2-2.
TABLE 2-2:DSP INSTRUCTION SUMMARY
InstructionAlgebraic OperationACC WB?
CLRA = 0Yes
EDA = (x – y)
EDACA = A + (x – y)
MACA = A + (x * y)Yes
MACA = A + x
MOVSACNo change in AYes
MPYA = x * yNo
MPY.NA = – x * yNo
MSCA = A – x * yYes
The DSP engine has various options selected through
various bits in the CPU Core Configuration register
(CORCON), as listed below:
1.Fractional or integer DSP multiply (IF).
2.Signed or unsigned DSP multiply (US).
3.Conventional or convergent rounding (RND).
4.Automatic saturation on/off for ACCA (SATA).
5.Automatic saturation on/off for ACCB (SATB).
6.Automatic saturation on/off for writes to data
memory (SATDW).
The 17 x 17-bit multiplier is capable of signed or
unsigned operati on and can mul tiplex i ts ou tput usi ng a
scaler to support either 1.31 fractional (Q31) or 32-bit
integer results. Unsigned operands are zero-extended
into the 17th bit of the multiplier input value. Signed
operands are sign-exten ded into the 17th bit of the mu ltiplier input value. The output of the 17 x 17-bit multiplier/scaler is a 33-bit value which is sign-extended to
40 bits. Integer data is inherently represented as a
signed two’s complement value, where the MSB is
defined as a sign bit. Generally speaking, the range of
an N-bit two’s compleme nt in teger i s -2
For a 16-bit integer, the data range is -32768 (0x8000)
to 32767 (0x7FFF) including ‘0’. For a 32-bit integer,
the data range is -2,147,483,648 (0x8000 0000) to
2,147,483,645 (0x7FFF FFFF).
When the multiplier is configured for fractional multiplication, the data is represented as a two’s complement
fraction, where the M SB is defined as a sign b it and the
radix point is impl ied to lie just after the sign b it (QX format). The range of an N-bit two’s complement fraction
with this implied radix point is -1.0 to (1 – 2
16-bit fraction, the Q15 data range is -1.0 (0x8000) to
0.999969482 (0x7FFF) including ‘0’ and has a precision of 3.01518x10
multiply operation genera tes a 1.3 1 produ ct, whi ch ha s
a precision of 4.65661 x 10
The same multiplier is used to support the MCU multiply instructions, which include integer 16-bit signed,
unsigned and mixed sign multiplies.
The MUL instruction can be directed to use byte or
word-sized operands. Byte operands direct a 16-bit
result. Word op erands direct a 32-bi t result to the s pecified register(s) in the W array.
-5
. In Fractional mode, the 16x16
-10
.
N-1
to 2
1-N
N-1
– 1.
). For a
2.4.2DATA ACCUMULATORS AND
ADDER/SUBTRACTER
The data accumulator consists of a 40-bit adder/
subtracter with automatic sign extension logic. It can
select one of two accumulators (A or B) as its preaccumulation source and post-accumulation destination. For the ADD and LAC instructions, the data to be
accumulated or load ed ca n be optio nally sca led v ia th e
barrel shifter prior to accumulation.
2.4.2.1Adder/Subtracter, Overflow and
Saturation
The adder/subtracter is a 40-bit adder with an optional
zero input into one side and either true or complement
data into the other input. In the case of addition, the
carry/borrow
true data (not complemented), whereas in the case of
subtraction, the carry/bo rrow
other input is complemented. The adder/subtracter
generates overflow Status bits SA/SB and OA/OB,
which are latched and refle cted in the ST A T US register:
• Overflow from bit 39: this is a catastrophic
overflow in which the sign of the accumulator is
destroyed.
• Overflow into guard bits 32 through 39: this is a
recoverable overflow. This bit is set whenever all
the guard bits are not identical to each other.
The adder has an additional saturation block which
controls accumulat or data satu ration if selected . It uses
the result of the adder, the overflow Status bits
described above, and the SATA/B (CORCON<7:6>)
and ACCSAT (CORCON<4>) mode control bits to
determine when and to what value to saturate.
Six STATUS register bits have been provided to
support saturation and overflow. They are:
1.OA:
ACCA overflowed into guard bits
2.OB:
ACCB overflowed into guard bits
3.SA:
ACCA saturated (bit 31 overflow and sa turation)
or
ACCA overflowed into guard bits and saturated
(bit 39 overflow and s aturation)
4.SB:
ACCB saturated (bit 31 overflow and sa turation)
or
ACCB overflowed into guard bits and saturated
(bit 39 overflow and s aturation)
5.OAB:
Logical OR of OA and OB
6.SAB:
Logical OR of SA and SB
The OA and OB bits are modified each time data
passes through the adder/subtracter. When set, they
indicate that the most recent operation has overflowed
into the accumulator guard bits (bits 32 through 39).
The OA and OB bits can also optionally generate an
arithmetic warning trap when set and the corresponding overflow trap flag enable bit (OVATE, OVBTE) in
the INTCON1 register (refer to Section 8.0 “Inter-rupts”) is set. This allows the user to take immediate
action, for example, to correct system gain.
The SA and SB bits are modified each time data
passes through the adder/subtracter but can only be
cleared by the user. When set, th ey indicate th at the
accumulator has overfl owed it s m aximum range (b it 31
for 32-bit saturation or bit 39 for 40-bit saturation) and
will be saturated if saturation is enabled. When saturation is not enabled, SA and SB default to bit 39 overflow
and thus indicate that a catastrophic overflow has
occurred. If the COVT E bit in th e INTCO N1 regi ster is
set, SA and SB bits ge nerate an arithmet ic warning trap
when saturation is disabled.
The overflow and saturation Status bits can optionally
be viewed in the STATUS register (SR) as the lo gical
OR of OA and OB (in bit OAB) and the logical OR of SA
and SB (in bit SAB). This allows programmers to check
one bit in the STATUS register to determine if either
accumulator has overflowed, or one bit to determine if
either accumulator has s aturated. T his w ould be us eful
for complex number arithmetic which typically uses
both the accumulators.
The device supports three saturation and overflow
modes:
1.Bit 39 Overflow and Saturation:
When bit 39 overflow and saturation occurs, the
saturation logic loads the maximally positive 9.31
(0x7FFFFFFFFF) or maximally negative 9.31
value (0x8000000000) into the target accumulator. The SA or SB bit is set and remains set until
cleared by the user. This is referred to as ‘super
saturation’ and provides protection against erroneous data or unexpected algorithm problems
(e.g., gain calculations).
2.Bit 31 Overflow and Saturation:
When bit 31 overflow and saturation occurs, the
saturation logic then loads the maximally positive 1.31 value (0x007FFFFFFF) or maximally
negative 1.31 value (0x0080000000) into the
target accumulator. The SA or SB bit is set and
remains set until cleared by the user. When this
Saturation mode is in effect, the guard bits are
not used, so the OA, OB or OAB bits are never
set.
3.Bit 39 Catastrophic Overflow:
The bit 39 overflow Status bit from the adder is
used to set the SA or SB bit which remains set
until cleared by the user. No saturation operation
is performed and the accumulator is allowed to
overflow (destroying it s sign). If the C OVTE bit in
the INTCON1 register is set, a catastrophic
overflow can initiate a trap exception.
2.4.2.2Accumulator ‘Write-Back’
The MAC class of instructions (with the exception of
MPY, MPY.N, ED and EDAC) can optionally write a
rounded version of the high word (bits 31 through 16)
of the accumulator that is not targeted by the instructio n
into data spac e memory. The write is performed across
the X bus into combined X and Y address space. The
following addressing modes are supported:
1.W13, Register Direct:
The rounded contents of the non-target
accumulator are written into W13 as a 1.15
fraction.
2.[W13]+=2, Register Indirect with Post-Increment:
The rounded conten ts of the non- target accumulator are written into the address pointed to by
W13 as a 1.15 fraction. W13 is then
incremented by 2 (for a word write).
2.4.2.3Round Logic
The round logic is a combinational block which performs a conventional (biased) or convergent (unbiased) round function during an accumulator write
(store). The Round mode is determined by the state of
the RND bit in the CORCON register . It generates a 16bit, 1.15 data value, which is passed to the data space
write saturation logic. If rounding is no t indicated by the
instruction, a truncated 1.15 data value is stored and
the least significant word (lsw) is simply discarded.
Conventional rounding takes bit 15 of the accumulator,
zero-extends it and ad ds it to the AC CxH w ord (bi t s 16
through 31 of the accumulator). If the ACCxL word
(bits 0 through 15 of the accumulator) is between
0x8000 and 0xFFFF (0x8000 included), ACCxH is
incremented. If ACCx L is between 0x000 0 and 0x7FFF,
ACCxH is left unchanged. A conse que nc e of thi s alg orithm is that over a succession of random rounding
operations, the value tends to be biased slightly
positive.
Convergent (or unbiased) rounding operates in the
same manner as conventional rounding, except when
ACCxL equals 0x8000. If this is the case, the LSb
(bit 16 of the accumulator) of ACCxH is examined. If it
is ‘1’, ACCxH is incremented. If it is ‘0’, ACCxH is not
modified. As sumi ng t hat bi t 16 is effe cti vely r and om in
nature, this scheme w i ll re mo ve any rou ndi ng b ias th at
may accumulate.
The SAC and SAC.R instructions store either a truncated (SAC) or rounded (SAC.R) version of the c ontents
of the target ac cumu la tor to d ata memo ry via th e X bu s
(subject to data saturation, see Section 2.4.2.4 “DataSpace Write Saturation”). Note that for the MAC cl as s
of instructions, the accumulator write-back operation
functions in the same manner, addressing combined
MCU (X and Y) data space though the X bus. For this
class of instructions, the data is always subject to
rounding.
In addition to adder/subtrac ter saturation, writes to dat a
space may also be saturated but without affecting the
contents of the source accumulator. The data space
write saturation logic block accepts a 16-bit, 1.15 fractional value from the round logic block as its input,
together with overflow status from the original source
(accumulator) and the 16-bit round adder. These are
combined and used to select the appropriate 1.15
fractional value as output to write to data space
memory.
If the SATDW bit in the CORCON register is set, data
(after rounding or truncation) is tes te d for ove rflo w and
adjusted accordingly. For input data greater than
0x007FFF, data written to memory is force d to the maximum positi ve 1. 15 val ue, 0x 7FFF. For input data less
than 0xFF8000, da ta wr itten to me mory i s forced to th e
maximum negative 1.1 5 value, 0x8000. The MSb of the
source (bit 39) is used to determine the sign of the
operand being tested.
If the SA TDW bi t in the CORCON regis ter is not set , the
input data is always passed through unmodified under
all conditions.
2.4.3BARREL SHIFTER
The barrel shifter is capable of performing up to 16-bit
arithmetic or logic right shifts, or up to 16-bit left shifts
in a single c ycle. The sou rce can be ei ther of th e two
DSP accumul ators, or the X bus (t o support multi-bit
shifts of register or memory data).
The shifter requi res a signed binary val ue to de term in e
both the magnitude (num ber of bits) and direction of the
shift operation. A po sitive value shift s the operand right.
A negative value shifts the operand left. A value of ‘0’
does not modify the operand.
The barrel shifter is 40 bits wide, thereby obtaining a
40-bit result for DSP shift operati ons and a 16- bit result
for MCU shift operations. Data from the X bus is presented to the barrel shifter between bit positions 16 to
31 for right shift s, and bit pos itions 0 to 16 for left shift s.
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 ReferenceManual” (DS70046). For more informat ion on the device
instruction set and programming, refer to the “dsPIC30F/33F Programmer’s Reference Manual “ (DS70157).
3.1Program Address Space
The program address space is 4M instruction words.
The program sp ace mem ory map fo r the dsPI30 F2011/
2012 is shown in Figure 3-1. The program space
memory map for the dsPI30F3012/3013 is shown in
Figure 3-2.
Program memory is addres sable by a 24 -bit value from
either the 23-bit PC, table instruction Effective Address
(EA), or data space EA, when program space is
mapped into data space as defined by Table 3-1. Note
that the program space address is incremented by two
between successiv e progr am w ords in o rder to prov ide
compatibility with data space addressing.
User program space access is restricted to the lower
4M instruction word address range (0x000000 to
0x7FFFFE) for all accesses other than TBLRD/TBLWT,
which uses TBLPAG<7> to determine user or configuration space access. In Table 3-1, Program Space
Address Construction, bit 23 allows access to the
Device ID, the User ID and the Configuration bits.
Otherwise, bit 23 is always clear.