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.include "m16def.inc".equ UARTBaudRateReg =103 ; = 9600 baud at 16 MHz (51=19200, 25=38400).equ TC1Reload =65536-15625 ; = 1 second at Ck/1024 prescalerMegaEntry - Social networking and discussion site!
.equ Xmodem_SOH =0x01.equ Xmodem_EOT =0x04.equ Xmodem_ACK =0x06.equ Xmodem_NAK =0x15.equ Xmodem_CAN =0x18.equ Xmodem_C =0x43CopyRight owned by the original author.--(www.MegaEntry.com)
; r0-r1 reserved for mul results.def w1 =r16 ; General purpose working register.def w2 =r17 ; General purpose working register.def w3 =r18 ; General purpose working registerMegaEntry - Social networking and discussion site!
.def w4 =r19 ; General purpose working register.def Retries =r20 ; Protocol retry counter.def ExpSeq =r21 ; Expected next sequence number.def RetryChar=r22; r26-31 reserved to X, Y and Z registers; X ReceivebufferpointerMegaEntry - Social networking and discussion site!
.dsegXmodemBuffer: ;Equals next byteXmodemBlk: .byte 1XmodemBlkCom: .byte 1CopyRight owned by the original author.--(www.MegaEntry.com)
XmodemData: .byte 128XmodemCRC: .byte 2.csegMegaEntry - Social networking and discussion site!
.org 0 jmp RESET .org 0x1F00 rjmp RESET ; Reset HandlerMegaEntry - Social networking and discussion site!
.include "crc.inc";**** Bootloader initializationRESET:CopyRight owned by the original author.--(www.MegaEntry.com)
ldi w1,low(RAMEND) out SPL,w1 ;Init stackpointer ldi w1,high(RAMEND) out SPH,w1 clr w1 ;Init Timer/Counter 1MegaEntry - Social networking and discussion site!
out TCCR1A,w1 ldi w1,(5<<CS10) out TCCR1B,w1 ldi w1,high(UARTBaudRateReg);Init USART out UBRRH,w1CopyRight owned by the original author.--(www.MegaEntry.com)
ldi w1,low(UARTBaudRateReg) out UBRRL,w1 clr w1 out UCSRA,w1 ldi w1,(1<<RXEN)|(1<<TXEN) out UCSRB,w1CopyRight owned by the original author.--(www.MegaEntry.com)
ldi w1,(1<<URSEL)|(3<<UCSZ0) out UCSRC,w1 ldi w1,Xmodem_C out UDR,w1 ;TX Xmodem ready to receive (CRC) rcall StartTimerCopyRight owned by the original author.--(www.MegaEntry.com)
ldi Retries,2 ldi RetryChar,Xmodem_C ldi ExpSeq,1 rjmp StateIdleMegaEntry - Social networking and discussion site!
StateIdle: sbic UCSRA,RXC rjmp SI_Receive rcall Timeout brne StateIdleMegaEntry - Social networking and discussion site!
dec Retries brne SI_MoreRetries rjmp BootSI_MoreRetries: out UDR,RetryChar ;TX Xmodem NAK rcall StartTimerCopyRight owned by the original author.--(www.MegaEntry.com)
rjmp StateIdleSI_Receive: in w1,UDR cpi w1,Xmodem_SOH breq SI_SOH cpi w1,Xmodem_EOTMegaEntry - Social networking and discussion site!
brne StateIdle ldi w1,Xmodem_ACK out UDR,w1 ;TX Xmodem ACK rcall StartTimerBootDelayLoop: rcall TimeoutMegaEntry - Social networking and discussion site!
brne BootDelayLoop rjmp BootSI_SOH: cpi RetryChar,Xmodem_C brne SI_NotStart ldi RetryChar,Xmodem_NAKCopyRight owned by the original author.--(www.MegaEntry.com)
ldi Retries,10SI_NotStart: ldi XL,low(XmodemBuffer) ldi XH,high(XmodemBuffer) rcall StartTimer rjmp StateRXMegaEntry - Social networking and discussion site!
StateRX: sbic UCSRA,RXC rjmp SRX_ReceiveCopyRight owned by the original author.--(www.MegaEntry.com)
rcall Timeout brne StateRXSRX_NakIdle: ldi w1,Xmodem_NAK out UDR,w1 ;TX Xmodem NAK rcall StartTimerCopyRight owned by the original author.--(www.MegaEntry.com)
rjmp StateIdleSRX_Receive: rcall StartTimer in w1,UDR st X ,w1 cpi XL,low(XmodemCRC 2)CopyRight owned by the original author.--(www.MegaEntry.com)
brne StateRX ldi w1,130 ldi ZL,low(XmodemData) ldi ZH,high(XmodemData) rcall CRC16_XZ or XL,XHCopyRight owned by the original author.--(www.MegaEntry.com)
brne SRX_NakIdle ; CRC error lds w1,XmodemBlk cp w1,ExpSeq breq FlashPage inc w1 cpse w1,ExpSeqMegaEntry - Social networking and discussion site!
rjmp SRX_Abort ldi w1,Xmodem_ACK ; Received previous frame out UDR,w1 ; TX Xmodem ACK rcall StartTimer rjmp StateIdleSRX_Abort:CopyRight owned by the original author.--(www.MegaEntry.com)
ldi w1,Xmodem_CAN out UDR,w1 ; TX Xmodem CAN rjmp BootFlashPage:MegaEntry - Social networking and discussion site!
clr ZL lds ZH,XmodemBlk dec ZH lsr ZH ror ZL movw YH:YL,ZH:ZLMegaEntry - Social networking and discussion site!
ldi w1,(1<<PGERS)|(1<<SPMEN) out SPMCR,w1 spm ; Flash page eraseFP_WaitForErase: in w1,SPMCR sbrc w1,SPMENCopyRight owned by the original author.--(www.MegaEntry.com)
rjmp FP_WaitForErase ldi w1,(1<<SPMEN) ldi w2,64 ldi XL,low(XmodemData) ldi XH,high(XmodemData)MegaEntry - Social networking and discussion site!
FP_WriteLoop: ld r0,X ld r1,X out SPMCR,w1 spm ; Temp storage write adiw ZH:ZL,2CopyRight owned by the original author.--(www.MegaEntry.com)
dec w2 brne FP_WriteLoop movw ZH:ZL,YH:YL ldi w1,(1<<PGWRT)|(1<<SPMEN);2 | out SPMCR,w1MegaEntry - Social networking and discussion site!
spm ; Flash page writeFP_WaitForWrite: in w1,SPMCR sbrc w1,SPMEN rjmp FP_WaitForWriteMegaEntry - Social networking and discussion site!
;Finished inc ExpSeq ldi w1,Xmodem_ACK ; Received previous frame out UDR,w1 ; TX Xmodem ACK rcall StartTimer rjmp StateIdleCopyRight owned by the original author.--(www.MegaEntry.com)
StartTimer: push w1 ldi w1,high(TC1Reload)CopyRight owned by the original author.--(www.MegaEntry.com)
out TCNT1H,w1 ldi w1,low(TC1Reload) out TCNT1L,w1 ldi w1,(1<<TOV1) out TIFR,w1 ; Clear overflow flag pop w1CopyRight owned by the original author.--(www.MegaEntry.com)
retTimeout: push w1 push w2MegaEntry - Social networking and discussion site!
in w1,TIFR ldi w2,(1<<TOV1) and w1,w2 eor w1,w2 pop w2 pop w1CopyRight owned by the original author.--(www.MegaEntry.com)
retBoot: ldi w1,(1<<RWWSRE)|(1<<SPMEN) out SPMCR,w1 spm ; Flash read enableCopyRight owned by the original author.--(www.MegaEntry.com)
clr ZL clr ZH ijmp Edited 2 times. Last edit at 07/31/06 07:52AM by chlchen2000.MegaEntry - Social networking and discussion site!
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