Merge pull request #408 from TG9541/onewire

Onewire and minor UM/MOD improvement

forth.asm

@@ -1508,10 +1508,10 @@ UMMOD:
         CPW     X,YTEMP
         JRULT   MMSM1           ; X is still on the R-stack
         POPW    X               ; restore stack pointer
-        LDW     Y,#0xFFFF       ; overflow result:
-        LDW     (X),Y           ; quotient max. 16 bit value
         CLRW    Y
         LDW     (2,X),Y         ; remainder 0
+        DECW    Y
+        LDW     (X),Y           ; quotient max. 16 bit value
         RET
 MMSM1:
         LD      A,#16           ; loop count

inc/defconf.inc

@@ -4,7 +4,7 @@
 ;--------------------------------------------------------
         RELVER1          = 2    ; Revision digit 1
         RELVER0          = 7    ; Revision digit 0
-        PRE_REL          = 3    ; Pre Release digit 0 (0: release)
+        PRE_REL          = 0    ; Pre Release digit 0 (0: release)
 
         TERM_LINUX       = 1    ; LF terminates line
 

lib/CRC8

@@ -0,0 +1,28 @@
+\ 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

lib/LSHIFT

@@ -0,0 +1,15 @@
+\ 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$:
+;