Information

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SPDIP 28 16-Bit 40 null I/O number 21

dsPIC33F/PIC24H PROGRAMMING SPECIFICATION

5.9 Reading Configuration Memory

The procedure for reading configuration memory is

similar to the procedure for reading code memory,

except that 16-bit data words are read (with the upper

byte read being all ‘0’s) instead of 24-bit words. Since

there are twelve Configuration registers, they are read

one register at a time.

Table 5-9 shows the ICSP programming details for

reading all of the configuration memory. Note that the

TBLPAG register is hard coded to 0xF8 (the upper byte

address of configuration memory) and the read pointer,

W6, is initialized to 0x0000.

TABLE 5-9: SERIAL INSTRUCTION EXECUTION FOR READING ALL CONFIGURATION MEMORY

Command

(Binary)

Data

(Hex)

Description

Step 1: Exit the Reset vector.

0000

040200

000000

GOTO 0x200

NOP

Step 2: Initialize TBLPAG, the read pointer (W6) and the write pointer (W7) for TBLRD instruction.

0000

200F80

880190

EB0300

207847

000000

MOV #0xF8, W0

MOV W0, TBLPAG

CLR W6

MOV #VISI, W7

NOP

Step 3: Read the Configuration register and write it to the VISI register (located at 0x784) and clock out the

VISI register using the REGOUT command.

0000

0001

BA0BB6

000000

<VISI>

TBLRDL [W6++], [W7]

NOP

Clock out contents of VISI register.

Step 4: Repeat step 3 twelve times to read all the Configuration registers.

Step 5: Reset device internal PC.

0000

040200

000000

GOTO 0x200

NOP