DSPIC30F5013-20E/PT Microchip Technology, DSPIC30F5013-20E/PT Datasheet - Page 21

• Manufacturer Part Number: DSPIC30F5013-20E/PT
• Description: IC DSPIC MCU/DSP 66K 80TQFP
• Manufacturer: Microchip Technology
• Series: dsPIC™ 30Fr

Specifications of DSPIC30F5013-20E/PT

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 20 MIPS
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: AC'97, Brown-out Detect/Reset, I²S, LVD, POR, PWM, WDT
• Number Of I /o: 68
• Program Memory Size: 66KB (22K x 24)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 5.5 V
• Data Converters: A/D 16x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 80-TFQFP
• For Use With: DM300024 - KIT DEMO DSPICDEM 1.1XLT80PT3 - SOCKET TRAN ICE 80MQFP/TQFPAC164320 - MODULE SKT MPLAB PM3 80TQFPDM300004-2 - BOARD DEMO DSPICDEM.NET 2DM300004-1 - BOARD DEMO DSPICDEM.NET 1AC30F007 - MODULE SKT FOR DSPIC30F 80TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: DSPIC30F5013-20EP

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 satu-
ration is not enabled, SA and SB default to bit 39 over-
flow 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:
• Bit 39 Overflow and Saturation:
• Bit 31 Overflow and Saturation:
• Bit 39 Catastrophic Overflow:
© 2011 Microchip Technology Inc.
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 errone-
ous data, or unexpected algorithm problems (e.g.,
gain calculations).
When bit 31 overflow and saturation occurs, the
saturation logic then loads the maximally positive
1.31 value (0x007FFFFFFF), or maximally nega-
tive 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).
The bit 39 overflow Status bit from the adder is
used to set the SA or SB bit which remain 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 over-
flow can initiate a trap exception.
2.4.2.2
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:
• W13, Register Direct:
• [W13]+=2, Register Indirect with Post-Increment:
2.4.2.3
The round logic is a combinational block which per-
forms a conventional (biased) or convergent (unbi-
ased) 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 (lsw) is simply discarded.
Conventional rounding takes bit 15 of the accumulator,
zero-extends it 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 algo-
rithm is that over a succession of random rounding
operations, the value will tend 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. Assuming that bit 16 is effectively random in
nature, this scheme will remove any rounding bias that
may accumulate.
The SAC and SAC.R instructions store either a trun-
cated (SAC) or rounded (SAC.R) version of the contents
of the target accumulator to data memory via the X bus
(subject to data saturation, see
Space Write
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.
The rounded contents of the non-target
accumulator are written into W13 as a 1.15
fraction.
The rounded contents of the non-target accumu-
lator are written into the address pointed to by
W13 as a 1.15 fraction. W13 is then incremented
by 2 (for a word write).
dsPIC30F5011/5013
Saturation”). Note that for the MAC class
Accumulator ‘Write Back’
Round Logic
Section 2.4.2.4 “Data
DS70116J-page 21