;--------------------------------------------------------

RELVER1 =2 ; Revision digit1

RELVER0 =7 ; Revision digit0

PRE_REL =3 ; Pre Release digit0 (0: release)

PRE_REL =0 ; Pre Release digit0 (0: release)

TERM_LINUX =1 ; LF terminates line

\ STM8 eForth: CRC8 for 1-Wire protocol, polynomial x8 + x5 + x4 + 1

\ refer to github.com/TG9541/stm8ef/blob/master/LICENSE.md

\ implementation for 1-wire protocol

: CRC8 ( crc c -- crc ) [ \ 1-Wire CRC8

$A608 , \ LD A,#8 ; loop through 8 bits

$F7 C, \ LD (X),A ; use MSB as bit counter

$E601 , \ LD A,(1,X) ;

$E803 , \ 1$: XOR A,(3,X) ; crc XOR c.bit0

$46 C, \ RRC A ; to carry

$E603 , \ LD A,(3,X) ; crc -> A

$2402 , \ JRNC 0$

$A818 , \ XOR A,#0x18 ; apply x5 + x4

$46 C, \ 0$: RRC A ; apply x8 + 1

$E703 , \ LD (3,X),A ; update crc value

$6401 , \ SRL (1,X) ; next c.bit0

$E601 , \ LD A,(1,X)

$7A C, \ DEC (X) ; bit counter until 0

$26ED , \ JRNE 1$ ; loop?

$5C C, \ INCW X ; DROP

$5C C, \ INCW X

] ;

\\ Test

\ DALLAS MAXIM AN937 Figure 3 Example Calculation for DOW CRC

HEX 0 2 CRC8 1C CRC8 B8 CRC8 1 CRC8 0 CRC8 0 CRC8 0 CRC8 . DECIMAL \ -> A2

\ STM8eForth : LSHIFT TG9541-210301

\ refer to github.com/TG9541/stm8ef/blob/master/LICENSE.md

: LSHIFT ( n c - n ) \ shift n left c times

[ $5C C, \ INCW X

$F6 C, \ LD A,(X)

$5C C, \ INCW X

$4D C, \ TNZ A

$2705 , \ JREQ 1$

$6801 , \ 2$: SLA (1,X)

$79 C, \ RLC (X)

$4A C, \ DEC A

$26F8 , \ JRNE 2$

] \ 1$:

;