DSPIC33FJ128MC804-H/ML Microchip Technology, DSPIC33FJ128MC804-H/ML Datasheet - Page 70

• Manufacturer Part Number: DSPIC33FJ128MC804-H/ML
• Description: 16-bit DSC, 128KB Flash, Motor, CAN, DMA, 40 MIPS, NanoWatt 44 QFN 8x8x0.9mm TUB
• Manufacturer: Microchip Technology
• Series: dsPIC™ 33Fr

Specifications of DSPIC33FJ128MC804-H/ML

• Core Processor: dsPIC
• Core Size: 16-Bit
• Speed: 20 MIPS
• Connectivity: CAN, I²C, IrDA, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, DMA, Motor Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 35
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 9x10b/12b, D/A 6x16b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 140°C
• Package / Case: 44-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

dsPIC33FJ32MC302/304, dsPIC33FJ64MCX02/X04 AND dsPIC33FJ128MCX02/X04
4.4.3
Modulo Addressing can be applied to the Effective
Address (EA) calculation associated with any W
register. Address boundaries check for addresses
equal to:
• The upper boundary addresses for incrementing
• The lower boundary addresses for decrementing
It is important to realize that the address boundaries
check for addresses less than or greater than the upper
(for incrementing buffers) and lower (for decrementing
buffers) boundary addresses (not just equal to).
Address changes can, therefore, jump beyond
boundaries and still be adjusted correctly.
4.5
Bit-Reversed Addressing mode is intended to simplify
data reordering for radix-2 FFT algorithms. It is
supported by the X AGU for data writes only.
The modifier, which can be a constant value or register
contents, is regarded as having its bit order reversed.
The address source and destination are kept in normal
order. Thus, the only operand requiring reversal is the
modifier.
4.5.1
Bit-Reversed Addressing mode is enabled in any of
these situations:
• BWM bits (W register selection) in the MODCON
• The BREN bit is set in the XBREV register
• The addressing mode used is Register Indirect
If the length of a bit-reversed buffer is M = 2
the last ‘N’ bits of the data buffer start address must
be zeros.
DS70291E-page 70
buffers
buffers
Note:
register are any value other than ‘15’ (the stack
cannot be accessed using Bit-Reversed
Addressing)
with Pre-Increment or Post-Increment
Bit-Reversed Addressing
MODULO ADDRESSING
APPLICABILITY
The modulo corrected effective address is
written back to the register only when
Pre-Modify or Post-Modify Addressing
mode is used to compute the effective
address. When an address offset (such as
[W7 + W2]) is used, Modulo Address
correction is performed but the contents of
the register remain unchanged.
BIT-REVERSED ADDRESSING
IMPLEMENTATION
N
bytes,
XB<14:0> is the Bit-Reversed Address modifier, or
‘pivot point,’ which is typically a constant. In the case of
an FFT computation, its value is equal to half of the FFT
data buffer size.
When enabled, Bit-Reversed Addressing is executed
only for Register Indirect with Pre-Increment or
Post-Increment Addressing and word-sized data
writes. It does not function for any other addressing
mode or for byte-sized data, and normal addresses are
generated instead. When Bit-Reversed Addressing is
active, the W Address Pointer is always added to the
address modifier (XB), and the offset associated with
the Register Indirect Addressing mode is ignored. In
addition, as word-sized data is a requirement, the LSb
of the EA is ignored (and always clear).
If Bit-Reversed Addressing has already been enabled
by setting the BREN bit (XBREV<15>), a write to the
XBREV register should not be immediately followed by
an indirect read operation using the W register that has
been designated as the bit-reversed pointer.
Note:
Note:
All bit-reversed EA calculations assume
word-sized data (LSb of every EA is
always clear). The XB value is scaled
accordingly to generate compatible (byte)
addresses.
Modulo Addressing and Bit-Reversed
Addressing
together. If an application attempts to do
so, Bit-Reversed Addressing assumes
priority when active for the X WAGU and X
WAGU, Modulo Addressing is disabled.
However, Modulo Addressing continues to
function in the X RAGU.
© 2011 Microchip Technology Inc.
should
not
be
enabled