tiny bootloader for 16f887

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Chao anh NAM
em tim tren mang duoc chuong trinh bootloader cho pic 16f887 nhung em muon cau hinh cho cac thong so sau
thach anh 20MHZ
baudrate 9600
anh co the chinh sua giup em
cam on anh
day la chuong trinh



radix DEC
LIST P=16F887, F=INHX8M ; change also: Configure->SelectDevice from Mplab

; auto-start at 4MHz internal osc
xtal EQU 4000000 ; you may also want to change: _HS_OSC _XT_OSC
baud EQU 19200 ; standard TinyBld baud rates: 115200 or 19200
;xtal EQU 4000000 ; you may also want to change: _HS_OSC _XT_OSC
;baud EQU 19200 ; standard TinyBld baud rates: 115200 or 19200

; The above 3 lines can be changed and buid a bootloader for the desired frequency (and PIC type)

;************************************************* *******************
; Tiny Bootloader 16FxxxA series Size=100words
; claudiu.chiculita@ugal.ro
; http://www.etc.ugal.ro/cchiculita/so...bootloader.htm
;************************************************* *******************

#include "../icdpictypes.inc" ;takes care of: #include "p16fxxxA.inc", max_flash, IdTypePIC
#include "../spbrgselect.inc"
#include "../bankswitch.inc"
#define first_address max_flash-100 ; 100 word in size

__CONFIG _CONFIG1, _LVP_OFF & _FCMEN_OFF & _IESO_OFF & _BOR_OFF & _CPD_OFF & _CP_OFF & _MCLRE_ON & _PWRTE_ON & _WDT_OFF & _INTRC_OSC_NOCLKOUT
__CONFIG _CONFIG2, _WRT_OFF & _BOR21V

errorlevel 1, -305 ; suppress warning msg that takes f as default


cblock 0x20
buffer:80
endc

cblock 0x78
crc
contor
i
cnt1
cnt2
cnt3
flag
endc


SendL macro car
movlw car
movwf TXREG
endm

;0000000000000000000000000 RESET 00000000000000000000000000

ORG 0x0000
PAGESEL IntrareBootloader
GOTO IntrareBootloader

;view with TabSize=4
;&&&&&&&&&&&&&&&&&&&&&&& START &&&&&&&&&&&&&&&&&
;---------------------- Bootloader ----------------------
;
;PC_flash: C1h AddrH AddrL nr ...(DataLo DataHi)... crc
;PIC_response: id K K


ORG first_address
nop
nop
nop
nop
org first_address+4
IntrareBootloader
;init serial port
clrf STATUS
bsf STATUS,RP0 ;BANK1_
movlw b'00100100'
movwf TXSTA
movlw spbrg_value
movwf SPBRG
BANK0_
movlw b'10010000'
movwf RCSTA
;wait for computer
call Receive
sublw 0xC1 ;Expect C1
skpz
goto way_to_exit
SendL IdTypePIC ;PIC type
;SendL IdSoftVer ;firmware ver x
MainLoop
clrf STATUS ;bank0
SendL 'K'
mainl
clrf crc
call Receive ;H
bsf STATUS,RP1 ;bank2
movwf EEADRH
movwf flag ;used to detect if is eeprom
call Receive ;L
bsf STATUS,RP1 ;bank2
movwf EEADR

call Receive ;count
movwf contor
movwf i
incf i
movlw buffer-1
movwf FSR
rcvoct
call Receive
incf FSR
movwf INDF
decfsz i
goto rcvoct

movf crc,f ;check checksum
skpz
goto ziieroare
;write
bsf STATUS,RP1 ;bank switch 0->2
movlw buffer
movwf FSR
writeloop ; write 2 bytes = 1 instruction
clrwdt
movf INDF,w
movwf EEDATA
incf FSR
movf INDF,w
movwf EEDATH
incf FSR
BANK3_ ;bank 2->3
bcf EECON1,EEPGD
btfss flag,6 ;is eeprom (or flash)
bsf EECON1,EEPGD
bsf EECON1,WREN
movlw 0x55
movwf EECON2
movlw 0xaa
movwf EECON2
bsf EECON1,WR
nop
nop
waitwre
; btfsc EECON1,WR ;for eeprom writes (wait to finish write)
; goto waitwre
bcf EECON1,WREN
BANK2_ ;bank2
incf EEADR ;does not cross zones
btfss flag,6 ; if writing to EEPROM, skip first counter dec.
decf contor
decfsz contor
goto writeloop

goto MainLoop
ziieroare
SendL 'N'
goto mainl


Receive
clrf STATUS
movlw xtal/2000000+1 ; for 20MHz => 11 => 1second
movwf cnt1
rpt2
clrf cnt2
rpt3
clrf cnt3
rptc
btfss PIR1,RCIF ;test RX
goto $+4
movf RCREG,w ;return in W
addwf crc,f ;compute checksum
return
clrwdt
decfsz cnt3
goto rptc
decfsz cnt2
goto rpt3
decfsz cnt1
goto rpt2
;timeout:
way_to_exit ;exit in all other cases; must be BANK0/1
;BANK0_
bcf RCSTA, SPEN ; deactivate UART
goto first_address
;************************************************* ************
; After reset
; Do not expect the memory to be zero,
; Do not expect registers to be initialised like in catalog.

END