Mercurial > hg > Members > kono > nitros9-code
view lib/alib/div16x16.as @ 3141:717ced83b885
coco3: Build SD card device descriptors for CoCo3FPGA
Added "CC3FPGAFLAGS = $(AFLAGS) -DCC3FPGA=1 $(FLAGS)" to
"level2/coco3/modules/makefile" for flagging Coco3FPGA specific features
in modules sources.
Added "llcoco3fpga", "ddsd0_coco3fpga", "sd0_coco3fpga", and
"sd1_coco3fpga" to the "coco3/modules/makefile" - RBF section, which
also now adds all to the "NITROS9/MODULES/RBF" on all disk images for
building new Coco3FPGA disks from NitrOS9.
Added new descriptor section to the "level2/coco3/modules/makefile"
reflecting the new Coco3FPGA SD card descriptors and their flags.
| author | Bill Pierce <merlinious999@gmail.com> |
|---|---|
| date | Sat, 04 Feb 2017 11:06:28 +0100 |
| parents | 03f26e88b809 |
| children |
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********************************************* * 16 x 16 bit integer divide * OTHER MODULES NEEDED: none * ENTRY: D = divisor * X = dividend * EXIT: X = quotient * D = remainder nam 16x16 bit Divide ttl Assembler Library Module section .bss negcount rmb 1 endsect section .text * Signed Divide SDIV16: clr negcount,u PSHS D,X tst ,s bpl testquo ldd ,s comb coma addd #$0001 std ,s inc negcount,u testquo tst 2,s bpl ok ldd 2,s comb coma addd #$0001 std 2,s inc negcount,u ok puls d,x bsr DIV16 dec negcount,u bne goforit pshs d,x ldd ,s coma comb addd #$0001 std ,s ldd 2,s coma comb addd #$0001 std 2,s puls d,x goforit rts * Unsigned Divide DIV16: PSHS D,X save divisor & dividend LDA #16 bit counter PSHS A CLRA initialize remainder CLRB div1 ASL 4,S shift dividend & quotient ROL 3,S ROLB shift dividend into B ROLA CMPD 1,S trial subtraction reqd? BLO div2 SUBD 1,S yes, do subtraction INC 4,S increment quotient div2 DEC ,S count down another bit BNE div1 LDX 3,S get quotient LEAS 5,S clean stack RTS endsect