Datasheet

Table 30-5 SPM Programming Time
(1)
Symbol Min. Programming Time Max. Programming Time
Flash write (Page Erase, Page Write, and write Lock bits
by SPM)
3.7ms 4.5ms
Note: 1. Minimum and maximum programming time is per individual operation.
30.8.12. Simple Assembly Code Example for a Boot Loader
;-the routine writes one page of data from RAM to Flash
; the first data location in RAM is pointed to by the Y pointer
; the first data location in Flash is pointed to by the Z-
pointer
;-error handling is not included
;-the routine must be placed inside the Boot space
; (at least the Do_spm sub routine). Only code inside NRWW
section can
; be read during Self-Programming (Page Erase and Page Write).
;-registers used: r0, r1, temp1 (r16), temp2 (r17), looplo
(r24),
; loophi (r25), spmcsrval (r20)
; storing and restoring of registers is not included in the
routine
; register usage can be optimized at the expense of code size
;-It is assumed that either the interrupt table is moved to
the Boot
; loader section or that the interrupts are disabled.
.equ PAGESIZEB = PAGESIZE*2 ;PAGESIZEB is page size in BYTES,
not words
.org SMALLBOOTSTART
Write_page:
; Page Erase
ldi spmcsrval, (1<<PGERS) | (1<<SPMEN)
call Do_spm
; re-enable the RWW section
ldi spmcsrval, (1<<RWWSRE) | (1<<SPMEN)
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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