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scu-dsp/parse10: implement end of chunk and end of input detection

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This commit is contained in:
Zack Buhman 2025-08-10 00:04:12 -05:00
parent 55c38ebf5f
commit 4d51b47046
1 changed files with 42 additions and 22 deletions
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64
scu-dsp/parse10.asm
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@ -4,36 +4,55 @@
;; mov mc0,ra0
;; variables:
;; m0[0] dma read start address (global)
;; m0[0]
;; m0[1] dma read value (local); post-shift 4-byte remainder (global)
;; m0[2] saved accumulator (global)
caller_setup:
mov 0,ct0
;; start address
mov mc0,ra0
mov 2,ct0
;; mov 0,mc0
setup:
;; [X ] [Y ] [D1 ]
mov 1,ct0
mov 0,ct3
mov 0,mc0
mov 0,mc0
mvi parse_base10,pc
mov 1,lop
;; parse_base10 return
mov all,mc3
mvi parse_base10,pc
mov 1,lop
;; parse_base10 return
mov all,mc3
nop
nop
nop
parse_base10:
next_chunk:
clr a mov 1,ct0
;; [X ] [Y ] [D1 ]
mov 1,ct0
mov m0,p mov m0,a
add
jmp nz,parse_loop
clr a ; delay slot
dma_next_chunk:
;; dma d0,mc0,1
;; begin fake number 0x39322033 "92 3"
mvi 0x393220,pl
add mov alu,a mov 0x33,pl
rl8 mov alu,a
rl8 mov alu,a mov 1,ct0
add mov all,mc0
;; end fake number
post_dma_load:
end_dma_next_chunk:
parse_loop:
;; extract first (leftmost) digit
mov 1,ct0
mov mc0,a mov 0x7f,pl
rl8 mov alu,a ;;mov all,mc0 ; m0[1] 0x20323339
;; multiply saved accumulator by 10
;; [X ] [Y ] [D1 ]
mov m0,y mov 10,rx ; m0[2] 0x00000000
and mov all,pl
or
jmp s,end_of_input
rl8 mov alu,a mov 10,rx ; m0[2] 0x00000000
jmp z,dma_next_chunk
and mov m0,y mov all,pl
;; MUL: post-multiplication accumulator
;; P: post-mask digit
@ -41,8 +60,6 @@ post_dma_load:
mov 1,ct0
xor clr a mov all,mc0 ; m0[1] 0x20323300
;; FIXME: if 0x00 jump to "end of input"?
add mov alu,a mov 0x30,pl ; 0x30 ascii '0'
;; A: post-mask digit
@ -52,7 +69,7 @@ post_dma_load:
;; if ((0x39 - 0x30) < 0) goto non_digit;
jmp s,non_digit
;; possibly set S flag for `jmp ns,non_digit`
sub ; sub in delay slot
sub mov 2,ct0 ; sub in delay slot
;; if (((0x39 - 0x30) - 10) >= 0) goto non_digit;
jmp ns,non_digit
mov mul,p mov 2,ct0 ; mov in delay slot
@ -60,14 +77,17 @@ post_dma_load:
digit:
;; we have a valid digit; add it to the accumulator; save to m0[2]
;; [X ] [Y ] [D1 ]
jmp post_dma_load
jmp parse_loop
add mov all,mc0 ; add in delay slot ; m0[2] 0x00000009
non_digit:
;; this is not a valid digit; return the accumulator
;; this is not a valid digit; return and clear the accumulator as A
;; [X ] [Y ] [D1 ]
btm
clr a ; clr in delay slot
mov m0,a mov 0,mc0 ; clr in delay slot ; m0[2]
;; m0:
;; 00000000 32330000 00000009 0000000
end_of_input:
btm
clr a