DSPIC33FJ128GP310A-I/PT Microchip Technology, DSPIC33FJ128GP310A-I/PT Datasheet - Page 38

• Manufacturer Part Number: DSPIC33FJ128GP310A-I/PT
• Description: IC DSPIC MCU/DSP 128K 100-TQFP
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33Fr

Specifications of DSPIC33FJ128GP310A-I/PT

• Program Memory Type: FLASH
• Program Memory Size: 128KB (128K x 8)
• Package / Case: 100-TFQFP
• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 40 MIPs
• Connectivity: I²C, IrDA, LIN, SPI, UART/USART
• Peripherals: AC'97, Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
• Number Of I /o: 85
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 32x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Product: DSCs
• Data Bus Width: 16 bit
• Processor Series: DSPIC33F
• Core: dsPIC
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 85
• Data Ram Size: 16 KB
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52713-733, 52714-737, 53276-922, EWDSPIC
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, DM240001, DV164033
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 876-1001 - DSPIC33 BREAKOUT BOARD
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

dsPIC33FJXXXGPX06A/X08A/X10A
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, they indicate that the
accumulator has overflowed its maximum range (bit 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 COVTE bit in the
INTCON1 register is set, SA and SB bits will generate
an arithmetic warning trap when saturation is disabled.
The Overflow and Saturation Status bits can optionally
be viewed in the STATUS Register (SR) as the logical
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 saturated. This would be useful
for complex number arithmetic which typically uses
both the accumulators.
The device supports three Saturation and Overflow
modes:
1.
2.
3.
DS70593B-page 38
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
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
problems (e.g., gain calculations).
Bit 31 Overflow and Saturation:
When bit 31 overflow and saturation occurs, the
saturation logic then loads the maximally
positive
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).
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 its sign). If the COVTE bit in
the INTCON1 register is set, a catastrophic
overflow can initiate a trap exception.
(0x8000000000),
1.31
data
value
or
unexpected
(0x007FFFFFFF),
into
the
algorithm
target
or
Preliminary
3.6.2.2
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 instruction
into data space memory. The write is performed across
the X bus into combined X and Y address space. The
following addressing modes are supported:
1.
2.
3.6.2.3
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
16-bit, 1.15 data value which is passed to the data
space write saturation logic. If rounding is not indicated
by the instruction, a truncated 1.15 data value is stored
and the least significant word is simply discarded.
Conventional rounding zero-extends bit 15 of the
accumulator and adds it to the ACCxH word (bits 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 ACCxL is between 0x0000 and 0x7FFF,
ACCxH is left unchanged. A consequence of this
algorithm 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. In this case, the Least
Significant bit (bit 16 of the accumulator) of ACCxH is
examined. If it is ‘1’, ACCxH is incremented. If it is ‘0’,
ACCxH is not modified. Assuming that bit 16 is
effectively random in nature, this scheme removes any
rounding bias that may accumulate.
The SAC and SAC.R instructions store either a
truncated (SAC), or rounded (SAC.R) version of the
contents of the target accumulator to data memory via
the
Section 3.6.2.4 “Data Space Write Saturation”). For
the MAC class of instructions, the accumulator
write-back operation will function 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.
W13, Register Direct:
The rounded contents of the non-target
accumulator are written into W13 as a
1.15 fraction.
[W13]+ = 2, Register Indirect with Post-Increment:
The rounded contents 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).
X
bus,
Accumulator ‘Write Back’
Round Logic
subject
 2009 Microchip Technology Inc.
to
data
saturation
(see