
2011-2012 Microchip Technology Inc.
Preliminary
DS70657E-page 117
dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/50X, AND PIC24EPXXXGP/MC20X
5.0
FLASH PROGRAM MEMORY
The dsPIC33EPXXXGP50X, dsPIC33EPXXXMC20X/
50X, and PIC24EPXXXGP/MC20X devices contain
internal Flash program memory for storing and
executing application code. The memory is readable,
writable and erasable during normal operation over the
entire VDD range.
Flash memory can be programmed in two ways:
In-Circuit Serial Programming (ICSP)
programming capability
Run-Time Self-Programming (RTSP)
ICSP
allows
for
a
dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X, and PIC24EPXXXGP/
MC20X device to be serially programmed while in the
end application circuit. This is done with two lines for
programming clock and programming data (one of the
alternate programming pin pairs: PGECx/PGEDx), and
three other lines for power (VDD), ground (VSS) and
Master Clear (MCLR). This allows customers to
manufacture boards with unprogrammed devices and
then program the device just before shipping the
product. This also allows the most recent firmware or a
custom firmware to be programmed.
RTSP is accomplished using TBLRD (table read) and
TBLWT (table write) instructions. With RTSP, the user
application can write program memory data a single
program memory word, and erase program memory in
blocks or ‘pages’ of 1024 instructions (3072 bytes) at a
time.
5.1
Table Instructions and Flash
Programming
Regardless of the method used, all programming of
Flash memory is done with the table read and table
write instructions. These allow direct read and write
access to the program memory space from the data
memory while the device is in normal operating mode.
The 24-bit target address in the program memory is
formed using bits <7:0> of the TBLPAG register and the
Effective Address (EA) from a W register specified in
The TBLRDL and the TBLWTL instructions are used to
read or write to bits <15:0> of program memory.
TBLRDL and TBLWTL can access program memory in
both Word and Byte modes.
The TBLRDH and TBLWTH instructions are used to read
or write to bits <23:16> of program memory. TBLRDH
and TBLWTH can also access program memory in Word
or Byte mode.
FIGURE 5-1:
ADDRESSING FOR TABLE REGISTERS
Note 1: This data sheet summarizes the features
of
the
dsPIC33EPXXXGP50X,
dsPIC33EPXXXMC20X/50X,
and
PIC24EPXXXGP/MC20X
families
of
devices. It is not intended to be a compre-
hensive reference source. To comple-
ment the information in this data sheet,
refer to Section 5. “Flash Program-
ming” (DS70609) of the “dsPIC33E/
PIC24E Family Reference Manual”,
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
this data sheet for device-specific register
and bit information.
0
Program Counter
24 bits
Program Counter
TBLPAG Reg
8 bits
Working Reg EA
16 bits
Byte
24-bit EA
0
1/0
Select
Using
Table Instruction
Using
User/Configuration
Space Select