Rainbow-electronics Atmega169L Uživatelský manuál stáhnout pdf (Strana 264)

264

ATmega169V/L

2514A–AVR–08/02

Note: 1. Z15:Z14: always ignored

Z0: should be zero for all SPM commands, byte select for the LPM instruction.

See “Addressing the Flash During Self-Programming” on page 257 for details about

the use of Z-pointer during Self-Programming.

Table 115. Explanation of different variables used in Figure 117 and the mapping to the

Z-pointer

(1)

Variable

Corresponding

Z-value 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 six 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.

ZPAGEMS

Z6 Bit in Z-register that is mapped to PCMSB.

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)

1 2 ... 259 260 261 262 263 264 265 266 267 268 269 ... 316 317

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Rainbow-electronics Atmega169L Uživatelský manuál Strana 264