
M68HC11
REFERENCE MANUAL
BOOTLOADER LISTINGS
MOTOROLA
B-15
Listing - MC68HC811E2 Bootloader (With Security)
Sheet 4 of 5
* IF DATA = $FF, THEN /16 IS CORRECT BAUD
CMPA
#$FF
BEQ
BAUDOK
* ELSE CHANGE TO /104 (/13 &/8) 1200 @ 2MHZ
BSET
BAUD,X $33
* THEN DOWNLOAD 256 BYTE PROGRAM
BAUDOK
EQU
*
LDY
#$0000
* READ IN PROGRAM AND PUT INTO RAM
BK2
EQU
*
BRCLR
SCSR,X $20 *
LDAA
SCDAT,X
STAA
$00,Y
STAA
SCDAT,X
INY
* UNTIL THE END IS REACHED
CPY
#$0100
BNE
BK2
*************************************************
* ALL START USER’S PROGRAM
STAR
EQU
*
JMP
$0000
bfa4 81 ff
bfa6 27 03
bfa8 1c 2b 33
bfab
bfab 18 ce 00 00
INIT POINTER
bfaf
bfaf 1f 2e 20 fc
bfb3 a6 2f
bfb5 18 a7 00
bfb8 a7 2f
bfba 18 08
WAIT FOR RDRF
HANDSHAKE
bfbc 18 8c 01 00
bfc0 26 ed
bfc2
bfc2 7e 00 00
*****************************************************
* EEPROM ERASE SUBROUTINE
*
* ASSUMES CALLING ROUTINE HAS ALREADY SET ERASE
* AND EELAT BITS, AS WELL AS ACCESSED CONFIG REG
* IF THAT IS TO BE ERASED
*
* ENTRY X = $1000
* EXIT X = $1000, Y = $0000
bfc5
ERASE
* SET EEPGM BIT
EQU
*
bfc5 1c 3b 01
BSET
PPROG,X $01
* 10 MILLISEC DELAY @ 2.1 MHZ
LDY
BK1
DEY
BNE
* TURN OFF EEPGM, ERASE AND EELAT BITS
CLR
PPROG,X
RTS
bfc8 18 ce 0b b8
bfcc 18 09
bfce 26 fc
#3000
BK1
bfd0 6f 3b
bfd2 39