check in Z180 subtree

[z180-stamp.git] / Z180 / fifoio.180

diff --git a/Z180/fifoio.180 b/Z180/fifoio.180
new file mode 100644 (file)
index 0000000..27745d4
--- /dev/null
+++ b/Z180/fifoio.180
@@ -0,0 +1,128 @@
+       page    255\r
+       .z80\r
+       \r
+       global  f.init,f.in,f.out,f.i.st\r
+\r
+       extrn   buf.init\r
+\r
+       include config.inc\r
+       include z180reg.inc\r
+\r
+\r
+;--------------------------------------------------------------\r
+\r
+       dseg\r
+       \r
+\r
+       mkbuf   rx.buf,rx.buf_len\r
+       mkbuf   tx.buf,tx.buf_len\r
+\r
+\r
+;--------------------------------------------------------------\r
+\r
+       cseg\r
+;\r
+; FIFO channels for communication with stm32\r
+;\r
+; Init Serial I/O for console input and output\r
+;\r
+       \r
+f.init:\r
+       ld      ix,rx.buf\r
+       ld      a,rx.buf.mask\r
+       call    buf.init\r
+       ld      ix,tx.buf\r
+       ld      a,tx.buf.mask\r
+       jp      buf.init\r
+\r
+\r
+f.i.st:\r
+       push    ix\r
+       ld      ix,rx.buf               ;\r
+\r
+buf.empty:\r
+       ld      a,(ix+o.in_idx)         ;\r
+       sub     (ix+o.out_idx)          ;\r
+       pop     ix\r
+       ret     z\r
+       or      0ffh\r
+       ret\r
+       \r
+\r
+f.in:\r
+       push    ix\r
+       ld      ix,rx.buf               ;\r
+\r
+buf.get:\r
+       ld      a,(ix+o.out_idx)        ;\r
+bg.wait:\r
+       cp      (ix+o.in_idx)           ;\r
+       jr      z,bg.wait\r
+\r
+       push    hl                      ;\r
+       push    ix\r
+       pop     hl\r
+       add     a,l\r
+       ld      l,a\r
+       jr      nc,bg.nc\r
+       inc     h\r
+bg.nc:\r
+       ld      l,(hl)\r
+       \r
+       ld      a,(ix+o.out_idx)        ;\r
+       inc     a\r
+       and     (ix+o.mask)\r
+       ld      (ix+o.out_idx),a\r
+       \r
+       ld      a,l\r
+       pop     hl\r
+       pop     ix\r
+       ret\r
+\r
+\r
+f.o.st:\r
+       push    ix\r
+       ld      ix,tx.buf               ;\r
+\r
+buf.full:\r
+       ld      a,(ix+o.in_idx)         ;\r
+       inc     a\r
+       and     (ix+o.mask)\r
+       sub     (ix+o.out_idx)          ;\r
+       pop     ix\r
+       ret     z\r
+       or      0ffh\r
+       ret\r
+\r
+\r
+f.out:\r
+       push    ix\r
+       ld      ix,tx.buf               ;\r
+\r
+buf.put:\r
+       push    hl                      ;\r
+       push    bc\r
+       push    ix\r
+       pop     hl\r
+       ld      c,(ix+o.in_idx)         ;\r
+       ld      b,0\r
+       add     hl,bc\r
+       ld      b,a\r
+\r
+       ld      a,c                     ;\r
+       inc     a\r
+       and     (ix+o.mask)\r
+bp.wait:\r
+       cp      (ix+o.out_idx)          ;\r
+       jr      z,bp.wait\r
+       ld      (hl),b\r
+       ld      (ix+o.in_idx),a\r
+       \r
+       ld      a,b\r
+       pop     bc\r
+       pop     hl\r
+       pop     ix\r
+       ret\r
+\r
+       end\r
+\r