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4.6.15 Generic Pointers

Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types. There are 3 types of generic pointers currently implemented data, code and eeprom pointers. They are differentiated by the value of the 7th and 6th bits of the upper byte:

pointer type 7th bit 6th bit rest of the pointer description
data 1 0 uuuuuu uuuuxxxx xxxxxxxx a 12-bit data pointer in data RAM memory
code 0 0 uxxxxx xxxxxxxx xxxxxxxx a 21-bit code pointer in FLASH memory
eeprom 0 1 uuuuuu uuuuuuxx xxxxxxxx a 10-bit eeprom pointer in EEPROM memory
(unimplemented) 1 1 xxxxxx xxxxxxxx xxxxxxxx unimplemented pointer type

Generic pointer are read and written with a set of library functions which read/write 1, 2, 3, 4 bytes.


next up previous contents index
Next: 4.6.16 PIC16 C Libraries Up: 4.6 The PIC16 port Previous: 4.6.14 Interrupts   Contents   Index
2008-12-05