avr: more ringbuffer macros and code.

avr/common/ringbuffer_y.asm

@@ -0,0 +1,91 @@
+; ***************************************************************************
+; copyright   : (C) 2025 by Martin Preuss
+; email       : martin@libchipcard.de
+;
+; ***************************************************************************
+; * This file is part of the project "AqHome".                              *
+; * Please see toplevel file COPYING of that project for license details.   *
+; ***************************************************************************
+
+
+.equ RINGBUFFERY_OFFS_MAXSIZE  = 0
+.equ RINGBUFFERY_OFFS_USED     = 1
+.equ RINGBUFFERY_OFFS_READPOS  = 2
+.equ RINGBUFFERY_OFFS_WRITEPOS = 3
+.equ RINGBUFFERY_OFFS_DATA     = 4
+
+
+
+; ---------------------------------------------------------------------------
+; @routine RingBufferY_Init
+;
+; @param R16 size of ringbuffer
+; @param Y   base address of ringbuffer struct
+; @return CFLAG set if okay, cleared on error (i.e. buffer full)
+; @clobbers R17
+
+RingBufferY_Init:
+  std Y+RINGBUFFERY_OFFS_MAXSIZE, r16
+  rjmp RingBufferY_Reset
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine RingBufferY_WriteByte
+;
+; @param R16 byte to write
+; @param Y   base address of ringbuffer struct
+; @return CFLAG set if okay, cleared on error (i.e. buffer full)
+; @clobbers R17, R18, X
+
+RingBufferY_WriteByte:
+  m_ringbuffer_y_writebyte \
+    RINGBUFFERY_OFFS_MAXSIZE, \
+    RINGBUFFERY_OFFS_USED, \
+    RINGBUFFERY_OFFS_READPOS, \
+    RINGBUFFERY_OFFS_WRITEPOS, \
+    RINGBUFFERY_OFFS_DATA
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @macro m_ringbuffer_y_readbyte
+;
+; @param Y   base address of ringbuffer struct
+; @return CFLAG set if okay, cleared on error (i.e. buffer empty)
+; @return R16 byte read
+; @clobbers R17, R18, X
+
+RingBufferY_ReadByte:
+  m_ringbuffer_y_readbyte \
+    RINGBUFFERY_OFFS_MAXSIZE, \
+    RINGBUFFERY_OFFS_USED, \
+    RINGBUFFERY_OFFS_READPOS, \
+    RINGBUFFERY_OFFS_WRITEPOS, \
+    RINGBUFFERY_OFFS_DATA
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @macro m_ringbuffer_y_reset
+;
+; @param Y   base address of ringbuffer struct
+; @clobbers R17
+
+RingBufferY_Reset:
+  m_ringbuffer_y_reset \
+    RINGBUFFERY_OFFS_MAXSIZE, \
+    RINGBUFFERY_OFFS_USED, \
+    RINGBUFFERY_OFFS_READPOS, \
+    RINGBUFFERY_OFFS_WRITEPOS, \
+    RINGBUFFERY_OFFS_DATA
+  ret
+; @end
+
+
+