The following tables are the parameters used in the description of the self programming are given.
| BOOTSZ1 | BOOTSZ0 | Boot Size | Pages | Application Flash Section | Boot Loader Flash Section | End Application Section | Boot Reset Address (Start Boot Loader Section) |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 128 words | 2 | 0x0000 - 0x1F7F | 0x1F80 - 0x1FFF | 0x1F7F | 0x1F80 |
| 1 | 0 | 256 words | 4 | 0x0000 - 0x1EFF | 0x1F00 - 0x1FFF | 0x1EFF | 0x1F00 |
| 0 | 1 | 512 words | 8 | 0x0000 - 0x1DFF | 0x1E00 - 0x1FFF | 0x1DFF | 0x1E00 |
| 0 | 0 | 1024 words | 16 | 0x0000 - 0x1BFF | 0x1C00 - 0x1FFF | 0x1BFF | 0x1C00 |
| Section | Pages | Address |
|---|---|---|
| Read-While-Write section (RWW) | 112 | 0x0000 - 0x1BFF |
| No Read-While-Write section (NRWW) | 16 | 0x1C00 - 0x1FFF |
For details about these two section, please refer to NRWW – No Read-While-Write Section and RWW – Read-While-Write Section.
| Variable | Corresponding Z-value(1) | Description | |
|---|---|---|---|
| PCMSB | 12 | Most significant bit in the Program Counter. (The Program Counter is 13 bits PC[12:0]) | |
| PAGEMSB | 5 | Most significant bit which is used to address the words within one page (64 words in a page requires 6 bits PC [5:0]) | |
| ZPCMSB | Z13 | Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the ZPCMSB equals PCMSB + 1. | |
| ZPAGEMSB | Z6 | Bit in Z-register that is mapped to PAGEMSB. Because Z0 is not used, the ZPAGEMSB equals PAGEMSB + 1. | |
| PCPAGE | PC[12:6] | Z13:Z7 | Program counter page address: Page select, for page erase and page write |
| PCWORD | PC[5:0] | Z6:Z1 | Program counter word address: Word select, for filling temporary buffer (must be zero during page write operation) |
Z0: should be zero for all SPM commands, byte select for the LPM instruction.
Please refer to Addressing the Flash During Self-Programming or details about the use of Z-pointer during Self- Programming.