PIC24HJ12GP201 Datasheet, PDF (39/234 Pages) Microchip Technology – High-Performance, 16-Bit Microcontrollers

PIC24HJ12GP201/202
4.0 FLASH PROGRAM MEMORY
Note:
This data sheet summarizes the features
of the PIC24HJ12GP201/202 devices. It is
not intended to be a comprehensive
reference source. To complement the
information in this data sheet, refer to the
“PIC24H Family Reference Manual”.
Please see the Microchip web site
(www.microchip.com) for the latest
PIC24H Family Reference Manual
chapters.
The PIC24HJ12GP201/202 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 a PIC24HJ12GP201/202 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: PGC1/PGD1, PGC2/PGD2 or PGC3/PGD3),
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 digital signal controller 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 either in
blocks or ‘rows’ of 64 instructions (192 bytes) at a time
or a single program memory word, and erase program
memory in blocks or ‘pages’ of 512 instructions (1536
bytes) at a time.
4.1 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 table instruction, as shown in Figure 4-1.
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 4-1:
ADDRESSING FOR TABLE REGISTERS
24 bits
Using
Program Counter
0
Program Counter
0
Using
Table Instruction
1/0 TBLPAG Reg
8 bits
Working Reg EA
16 bits
User/Configuration
Space Select
24-bit EA
Byte
Select
© 2007 Microchip Technology Inc.
Preliminary
DS70282B-page 37