dsPIC33FJ32MC204 Microchip Technology, dsPIC33FJ32MC204 Datasheet - Page 54

• Manufacturer Part Number: dsPIC33FJ32MC204
• Description: (dsPIC33FJ16MC304 / dsPIC33FJ32MC20x) 16-bit Microcontrollers
• Manufacturer: Microchip Technology

4.2
The
dsPIC33FJ16MC304 Flash program memory array is
organized into rows of 64 instructions or 192 bytes.
RTSP allows the user application to erase a page of
memory, which consists of eight rows (512 instructions)
at a time, and to program one row or one word at a
time. Table 23-12 shows typical erase and program-
ming times. The 8-row erase pages and single row
write rows are edge-aligned from the beginning of pro-
gram memory, on boundaries of 1536 bytes and 192
bytes, respectively.
The program memory implements holding buffers that
can contain 64 instructions of programming data. Prior
to the actual programming operation, the write data
must be loaded into the buffers sequentially. The
instruction words loaded must always be from a group
of 64 boundary.
The basic sequence for RTSP programming is to set up
a Table Pointer, then do a series of TBLWT instructions
to load the buffers. Programming is performed by
setting the control bits in the NVMCON register. A total
of 64 TBLWTL and TBLWTH instructions are required
to load the instructions.
All of the table write operations are single-word writes
(two instruction cycles) because only the buffers are
written.
programming each row.
DS70283B-page 52
RTSP Operation
A
programming
dsPIC33FJ32MC202/204
cycle
is
required
and
Preliminary
for
4.3
Two SFRs are used to read and write the program
Flash memory: NVMCON and NVMKEY.
The NVMCON register (Register 4-1) controls which
blocks are to be erased, which memory type is to be
programmed and the start of the programming cycle.
NVMKEY is a write-only register that is used for write
protection. To start a programming or erase sequence,
the user application must consecutively write 0x55 and
0xAA to the NVMKEY register. Refer to Section 4.4
“Programming Operations” for further details.
4.4
A complete programming sequence is necessary for
programming or erasing the internal Flash in RTSP
mode. A programming operation is nominally 4 ms in
duration and the processor stalls (waits) until the
operation
(NVMCON<15>) starts the operation, and the WR bit is
automatically cleared when the operation is finished.
Control Registers
Programming Operations
is
finished.
© 2007 Microchip Technology Inc.
Setting
the
WR
bit