1 files changed, 128 insertions, 0 deletions
diff --git a/z180/fifoio.180 b/z180/fifoio.180
new file mode 100644
index 0000000..27745d4
--- /dev/null
+++ b/z180/fifoio.180
@@ -0,0 +1,128 @@
+	page	255
+	.z80
+	
+	global	f.init,f.in,f.out,f.i.st
+
+	extrn	buf.init
+
+	include config.inc
+	include	z180reg.inc
+
+
+;--------------------------------------------------------------
+
+	dseg
+	
+
+	mkbuf	rx.buf,rx.buf_len
+	mkbuf	tx.buf,tx.buf_len
+
+
+;--------------------------------------------------------------
+
+	cseg
+;
+; FIFO channels for communication with stm32
+;
+; Init Serial I/O for console input and output
+;
+	
+f.init:
+	ld	ix,rx.buf
+	ld	a,rx.buf.mask
+	call	buf.init
+	ld	ix,tx.buf
+	ld	a,tx.buf.mask
+	jp	buf.init
+
+
+f.i.st:
+	push	ix
+	ld	ix,rx.buf		;
+
+buf.empty:
+	ld	a,(ix+o.in_idx)		;
+	sub	(ix+o.out_idx)		;
+	pop	ix
+	ret	z
+	or	0ffh
+	ret
+	
+
+f.in:
+	push	ix
+	ld	ix,rx.buf		;
+
+buf.get:
+	ld	a,(ix+o.out_idx)	;
+bg.wait:
+	cp	(ix+o.in_idx)		;
+	jr	z,bg.wait
+
+	push	hl			;
+	push	ix
+	pop	hl
+	add	a,l
+	ld	l,a
+	jr	nc,bg.nc
+	inc	h
+bg.nc:
+	ld	l,(hl)
+	
+	ld	a,(ix+o.out_idx)	;
+	inc	a
+	and	(ix+o.mask)
+	ld	(ix+o.out_idx),a
+	
+	ld	a,l
+	pop	hl
+	pop	ix
+	ret
+
+
+f.o.st:
+	push	ix
+	ld	ix,tx.buf		;
+
+buf.full:
+	ld	a,(ix+o.in_idx)		;
+	inc	a
+	and	(ix+o.mask)
+	sub	(ix+o.out_idx)		;
+	pop	ix
+	ret	z
+	or	0ffh
+	ret
+
+
+f.out:
+	push	ix
+	ld	ix,tx.buf		;
+
+buf.put:
+	push	hl			;
+	push	bc
+	push	ix
+	pop	hl
+	ld	c,(ix+o.in_idx)		;
+	ld	b,0
+	add	hl,bc
+	ld	b,a
+
+	ld	a,c			;
+	inc	a
+	and	(ix+o.mask)
+bp.wait:
+	cp	(ix+o.out_idx)		;
+	jr	z,bp.wait
+	ld	(hl),b
+	ld	(ix+o.in_idx),a
+	
+	ld	a,b
+	pop	bc
+	pop	hl
+	pop	ix
+	ret
+
+	end
+