DSPIC30F5011-20I/PTG Microchip Technology, DSPIC30F5011-20I/PTG Datasheet - Page 32

• Manufacturer Part Number: DSPIC30F5011-20I/PTG
• Description: IC, DSC, 16BIT, 66KB, 40MHZ 5.5V TQFP-64
• Manufacturer: Microchip Technology
• Series: DsPIC30Fr

Specifications of DSPIC30F5011-20I/PTG

• Core Frequency: 40MHz
• Core Supply Voltage: 5.5V
• Embedded Interface Type: CAN, I2C, SPI, UART
• No. Of I/o's: 52
• Flash Memory Size: 66KB
• Supply Voltage Range: 2.5V To 5.5V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

dsPIC30F5011/5013
3.2.2
X data space is used by all instructions and supports all
Addressing modes. There are separate read and write
data buses. The X read data bus is the return data path
for all instructions that view data space as combined X
and Y address space. It is also the X address space
data path for the dual operand read instructions
(MAC class). The X write data bus is the only write path
to data space for all instructions.
The X data space also supports modulo addressing for
all
restrictions. Bit-reversed addressing is only supported
for writes to X data space.
The Y data space is used in concert with the X data
space by the MAC class of instructions (CLR, ED,
EDAC,
provide two concurrent data read paths. No writes
occur across the Y bus. This class of instructions
dedicates two W register pointers, W10 and W11, to
always address Y data space, independent of X data
space, whereas W8 and W9 always address X data
space. Note that during accumulator write back, the
data address space is considered a combination of X
and Y data spaces, so the write occurs across the X
bus. Consequently, the write can be to any address in
the entire data space.
The Y data space can only be used for the data
prefetch operation associated with the MAC class of
instructions. It also supports modulo addressing for
automated circular buffers. Of course, all other
instructions can access the Y data address space
through the X data path as part of the composite linear
space.
The boundary between the X and Y data spaces is
defined as shown in Figure 3-6 and is not user
programmable. Should an EA point to data outside its
own assigned address space, or to a location outside
physical memory, an all zero word/byte will be returned.
For example, although Y address space is visible by all
non-MAC instructions using any Addressing mode, an
attempt by a MAC instruction to fetch data from that
space using W8 or W9 (X space pointers) will
return 0x0000.
TABLE 3-2:
All effective addresses are 16 bits wide and point to
bytes within the data space. Therefore, the data space
address range is 64 Kbytes or 32K words.
DS70116H-page 32
EA = an unimplemented address
W8 or W9 used to access Y data
space in a MAC instruction
W10 or W11 used to access X
data space in a MAC instruction
instructions,
Attempted Operation
MAC,
DATA SPACES
MOVSAC,
EFFECT OF INVALID
MEMORY ACCESSES
subject
MPY,
to
MPY.N and MSC) to
Addressing
Data Returned
0x0000
0x0000
0x0000
mode
3.2.3
The core data width is 16 bits. All internal registers are
organized as 16-bit wide words. Data space memory is
organized in byte addressable, 16-bit wide blocks.
3.2.4
To
PIC
usage efficiency, the dsPIC30F instruction set supports
both word and byte operations. Data is aligned in data
memory and registers as words, but all data space EAs
resolve to bytes. Data byte reads will read the complete
word which contains the byte, using the LSb of any EA
to determine which byte to select. The selected byte is
placed onto the LSB of the X data path (no byte
accesses are possible from the Y data path as the MAC
class of instruction can only fetch words). That is, data
memory and registers are organized as two parallel
byte wide entities with shared (word) address decode
but separate write lines. Data byte writes only write to
the corresponding side of the array or register which
matches the byte address.
As a consequence of this byte accessibility, all effective
address calculations (including those generated by the
DSP operations which are restricted to word sized
data) are internally scaled to step through word aligned
memory. For example, the core would recognize that
Post-Modified Register Indirect Addressing mode
[Ws++] will result in a value of Ws+1 for byte operations
and Ws+2 for word operations.
All word accesses must be aligned to an even address.
Misaligned word data fetches are not supported so
care must be taken when mixing byte and word
operations, or translating from 8-bit MCU code. Should
a misaligned read or write be attempted, an address
error trap will be generated. If the error occurred on a
read, the instruction underway is completed, whereas if
it occurred on a write, the instruction will be executed
but the write will not occur. In either case, a trap will
then be executed, allowing the system and/or user to
examine the machine state prior to execution of the
address fault.
FIGURE 3-8:
®
0001
0003
0005
help
MCU devices and improve data space memory
15
DATA SPACE WIDTH
DATA ALIGNMENT
maintain
MSB
Byte1
Byte3
Byte5
DATA ALIGNMENT
backward
© 2008 Microchip Technology Inc.
8 7
LSB
Byte 0
Byte 2
Byte 4
compatibility
0
0000
0002
0004
with