Microchip Technology MA240017 Data Sheet

Page of 278
 2008-2011 Microchip Technology Inc.
DS39927C-page 45
PIC24F16KA102 FAMILY
5.0
FLASH PROGRAM MEMORY
The PIC24FJ64GA family of devices contains internal
Flash program memory for storing and executing appli-
cation code. The memory is readable, writable and
erasable when operating with V
DD
 over 1.8V.
Flash memory can be programmed in three ways:
• In-Circuit Serial Programming™ (ICSP™)
• Run-Time Self-Programming (RTSP)
• Enhanced In-Circuit Serial Programming 
(Enhanced ICSP)
ICSP allows a PIC24F16KA102 device to be serially
programmed while in the end application circuit. This is
simply done with two lines for the programming clock
and programming data (which are named PGCx and
PGDx, respectively), and three other lines for power
(V
DD
), ground (V
SS
) and Master Clear/Program Mode
Entry Voltage (MCLR/V
PP
). This allows customers to
manufacture boards with unprogrammed devices and
then program the microcontroller just before shipping
the product. This also allows the most recent firmware
or custom firmware to be programmed.
Real-Time Self-Programming (RTSP) is accomplished
using  TBLRD (table read) and TBLWT (table write)
instructions. With RTSP, the user may write program
memory data in blocks of 32 instructions (96 bytes) at a
time, and erase program memory in blocks of 32, 64 and
128 instructions (96,192 and 384 bytes) at a time.
The NVMOP<1:0> (NVMCON<1:0>) bits decide the
erase block size.
5.1
Table Instructions and Flash 
Programming
Regardless of the method used, Flash memory
programming is done with the table read and 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 the
TBLPAG<7:0> bits and the Effective Address (EA) from
a W register, specified in the table instruction, as
depicted 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:
This data sheet summarizes the features of
this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information on Flash Pro-
gramming, refer to the “PIC24F Family
Reference Manual”
Section 4. “Program
Memory”
 (DS39715).
24 Bits
Program
TBLPAG Reg
8 Bits
16 Bits
Using
Byte
24-Bit EA
1/0
Select
Table
Instruction
Counter
Using
User/Configuration
Space Select
Working Reg EA
0
Program Counter
0