at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 245

• Manufacturer Part Number: at90pwm81-16se
• Description: 8-bit Avr Microcontroller With 8k Bytes In- System Programmable Flash
• Manufacturer: ATMEL Corporation

7734M–AVR–03/10
.equ PAGESIZEB = PAGESIZE*2
.org SMALLBOOTSTART
Write_page:
Wrloop:
Rdloop:
Return:
; 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.
; Page Erase
ldi
call Do_spm
; re-enable the RWW section
ldi
call Do_spm
; transfer data from RAM to Flash page buffer
ldi
ldi
ld
ld
ldi
call Do_spm
adiw ZH:ZL, 2
sbiw loophi:looplo, 2
brne Wrloop
; execute Page Write
subi ZL, low(PAGESIZEB)
sbci ZH, high(PAGESIZEB)
ldi
call Do_spm
; re-enable the RWW section
ldi
call Do_spm
; read back and check, optional
ldi
ldi
subi YL, low(PAGESIZEB)
sbci YH, high(PAGESIZEB)
lpm
ld
cpse r0, r1
jmp
sbiw loophi:looplo, 1
brne Rdloop
; return to RWW section
; verify that RWW section is safe to read
in
sbrs temp1, RWWSB
ret
; re-enable the RWW section
ldi
call Do_spm
spmcrval, (1<<PGERS) | (1<<SPMEN)
spmcrval, (1<<RWWSRE) | (1<<SPMEN)
looplo, low(PAGESIZEB)
loophi, high(PAGESIZEB)
r0, Y+
r1, Y+
spmcrval, (1<<SPMEN)
spmcrval, (1<<PGWRT) | (1<<SPMEN)
spmcrval, (1<<RWWSRE) | (1<<SPMEN)
looplo, low(PAGESIZEB)
loophi, high(PAGESIZEB)
r0, Z+
r1, Y+
Error
temp1, SPMCSR
spmcrval, (1<<RWWSRE) | (1<<SPMEN)
; If RWWSB is set, the RWW section is not ready yet
;PAGESIZEB is page size in BYTES, not words
;init loop variable
;not required for PAGESIZEB<=256
;use subi for PAGESIZEB<=256
;restore pointer
;not required for PAGESIZEB<=256
;init loop variable
;not required for PAGESIZEB<=256
;restore pointer
;use subi for PAGESIZEB<=256
AT90PWM81
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