;-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
.org SMALLBOOTSTART
Write_page:
;PAGESIZEB is page size in BYTES, not words
; Page Erase
ldi spmcrval, (1<<PGERS) | (1<<SPMEN)
call Do_spm
; re-enable the RWW section
ldi spmcrval, (1<<RWWSRE) | (1<<SPMEN)
call Do_spm
; transfer data from RAM to Flash page buffer
ldi looplo, low(PAGESIZEB)
;init loop variable
ldi loophi, high(PAGESIZEB) ;not required for PAGESIZEB<=256
Wrloop:
ld
ld
r0, Y+
r1, Y+
ldi spmcrval, (1<<SPMEN)
call Do_spm
adiw ZH:ZL, 2
sbiw loophi:looplo, 2
brne Wrloop
;use subi for PAGESIZEB<=256
; execute Page Write
subi ZL, low(PAGESIZEB)
sbci ZH, high(PAGESIZEB)
;restore pointer
;not required for PAGESIZEB<=256
ldi spmcrval, (1<<PGWRT) | (1<<SPMEN)
call Do_spm
; re-enable the RWW section
ldi spmcrval, (1<<RWWSRE) | (1<<SPMEN)
call Do_spm
; read back and check, optional
ldi looplo, low(PAGESIZEB)
;init loop variable
ldi loophi, high(PAGESIZEB) ;not required for PAGESIZEB<=256
subi YL, low(PAGESIZEB)
sbci YH, high(PAGESIZEB)
Rdloop:
;restore pointer
lpm r0, Z+
ld
r1, Y+
cpse r0, r1
jmp Error
sbiw loophi:looplo, 1
brne Rdloop
;use subi for PAGESIZEB<=256
; return to RWW section
; verify that RWW section is safe to read
Return:
in
temp1, SPMCSR
sbrs temp1, RWWSB
ret
; If RWWSB is set, the RWW section is not ready yet
; re-enable the RWW section
ldi spmcrval, (1<<RWWSRE) | (1<<SPMEN)
call Do_spm
rjmp Return
276
AT90PWM2/3/2B/3B
4317J–AVR–08/10
ATMEL [ ATMEL ]
