]>
git.gir.st - Chiptunes-pms150c.git/blob - bsv.c
411bede5123c9c9f460a2c6e9bfbb9b146a9e922
3 typedef unsigned char u8
;
12 u8 mod3hi
, mod3lo
; //MEM
13 //todo: can mod3hi be aliased to tmp_1?
16 ADD (mod3lo
,acc
) // mod3lo = hi+lo
18 ADDC0 (acc
) // mod3hi, 1bit
24 AND (acc
, 0xf) // (mod3lo>>4)
25 XCH (mod3lo
) // acc=mod3lo, mod3lo=mod3lo>>4
26 AND (acc
, 0xF) // acc=mod3lo&0xf, mod3lo=mod3lo>>4
27 ADD (acc
, mod3lo
) // (mod3lo & 0xF)
31 AND (acc
, 0x3) // acc = (mod3lo & 0x3)
33 SR (mod3lo
) // (mod3lo >> 2)
37 AND (acc
, 0x3) // acc = (mod3lo & 0x3)
39 SR (mod3lo
) // (mod3lo >> 2)
43 /*T0SN FLAG.C (0x00.1)*/ if (flag_c
){ // skip if carry clear
48 // notes_ix_hi = always 0
55 /*T0SN FLAG.Z (0x00.0)*/ if(3&i2
) {// skip if !(3&i0)
56 SET1 (notes_ix
, 3) } // ix += 8 <=> ix |= 8
57 IDXM (acc
, notes
+notes_ix
)
59 //unrolled: https://git.gir.st/Chiptunes.git/blob/f8e0502:/foo.S#l113
60 u8 a2
= 0; // can probably be overloaded onto mul3lo/hi
62 u8 t
= acc
; // note input (as returned by idxm)
63 for (u8 loop
= 0; loop
< 8; loop
++) {
65 /*T1SN FLAG.C (0x00.1)*/ if (!flag_c
) // skip if carry set
81 //rom is not mmapped; must load into ram first
100 MOV (notes
[0x8], acc
)
101 MOV (notes
[0xD], acc
)
103 MOV (notes
[0x9], acc
)
104 MOV (notes
[0xC], acc
)
107 MOV (acc
, i2
)// "mov mem,mem"
108 MOV (n
, acc
)// does not exist
128 MOV (tmp_1
, acc
) // fresh tmp_1:
133 OR (acc
, tmp_1
) // tmp_1 done.
161 MOV (tmp_1
, acc
) // acc saved in tmp_1; fresh acc
163 // shift-divide by six
164 // note: i2 is max 0x78; so acc will <= 20. (breaks vor values >=128)
177 AND (acc
, tmp_1
) // acc restored from tmp_1
200 MOV (tmp_1
, acc
) // acc saved in tmp_1; fresh acc
202 // shift-divide by ten
203 // note: i2 is max 0x78; so acc will <= 12.
216 AND (acc
, tmp_1
) // acc restored from tmp_1
225 /*ADDC i1*/ i1
+= !i0
;
226 /*ADDC i2*/ i2
+= !i1
&& !i0
;
228 if(i2
== 0x78) break;