avr: started work on com2w_router for S03.

avr/modules/com2w_router/iface.asm

@@ -0,0 +1,175 @@
+; ***************************************************************************
+; copyright   : (C) 2026 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.   *
+; ***************************************************************************
+
+#ifndef AVR_MOD_COM2WROUTER_IFACE_ASM
+#define AVR_MOD_COM2WROUTER_IFACE_ASM
+
+
+
+; ***************************************************************************
+; defines
+
+.equ COM2WR_BUFFERSIZE              = NET_BUFFERS_SIZE-1
+
+
+.equ COM2WR_MODE_IDLE               = 0
+.equ COM2WR_MODE_SKIPPING           = 1
+.equ COM2WR_MODE_READING            = 2
+.equ COM2WR_MODE_WRITING            = 3
+.equ COM2WR_MODE_NUM                = 4
+
+
+.equ COM2WR_IFACE_OFFS_BEGIN        = NET_IFACE_SIZE
+.equ COM2WR_IFACE_OFFS_MODE         = COM2WR_IFACE_OFFS_BEGIN+0
+.equ COM2WR_IFACE_OFFS_MODECOUNTER  = COM2WR_IFACE_OFFS_BEGIN+1
+.equ COM2WR_IFACE_OFFS_CURRBYTE     = COM2WR_IFACE_OFFS_BEGIN+2
+.equ COM2WR_IFACE_OFFS_BITCOUNTER   = COM2WR_IFACE_OFFS_BEGIN+3
+.equ COM2WR_IFACE_OFFS_BUFPOS_LO    = COM2WR_IFACE_OFFS_BEGIN+4
+.equ COM2WR_IFACE_OFFS_BUFPOS_HI    = COM2WR_IFACE_OFFS_BEGIN+5
+.equ COM2WR_IFACE_OFFS_BUFUSED      = COM2WR_IFACE_OFFS_BEGIN+6
+.equ COM2WR_IFACE_OFFS_BUFLEFT      = COM2WR_IFACE_OFFS_BEGIN+7
+.equ COM2WR_IFACE_OFFS_BUFFER       = COM2WR_IFACE_OFFS_BEGIN+8
+
+.equ COM2WR_IFACE_SIZE              = COM2WR_IFACE_OFFS_BUFFER+COM2WR_BUFFERSIZE
+
+
+
+; ***************************************************************************
+; code
+
+.cseg
+
+
+
+; ---------------------------------------------------------------------------
+; @routine COM2WR_Iface_StartReading
+;
+; @param Y pointer to interface data in SDRAM
+; @clobbers r16, X
+
+COM2WR_Iface_StartReading:
+  rcall com2wrResetReadBuffer
+  ldi r16, COM2WR_MODE_READING
+  std Y+COM2WR_IFACE_OFFS_MODE, r16
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine COM2WR_Iface_StartSkipping
+;
+; @param Y pointer to interface data in SDRAM
+; @clobbers r16, X
+
+COM2WR_Iface_StartSkipping:
+  ldi r16, COM2WR_MODE_SKIPPING
+  std Y+COM2WR_IFACE_OFFS_MODE, r16
+  rcall com2wrResetReadBuffer
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine COM2WR_Iface_RecvHandleBit
+;
+; @param Y pointer to interface data in SDRAM
+; @param R18 current CLK bit
+; @param R19 current DATA bit
+; @clobbers
+
+COM2WR_Iface_RecvHandleBit:
+  ldd r16, Y+COM2WR_IFACE_OFFS_MODE
+  cpi r16, COM2WR_MODE_READING
+  breq COM2WR_Iface_RecvHandleBit_reading
+  cpi r16, COM2WR_MODE_IDLE
+  breq COM2WR_Iface_RecvHandleBit_idle
+  rjmp COM2WR_Iface_RecvHandleBit_ret
+COM2WR_Iface_RecvHandleBit_reading:
+  tst r18                                  ; CLK now HIGH?
+  breq COM2WR_Iface_RecvHandleBit_ret      ; nope, ignore
+  ; TODO: read bit
+  rjmp COM2WR_Iface_RecvHandleBit_ret
+COM2WR_Iface_RecvHandleBit_idle:
+  tst r18                                  ; CLK became LOW?
+  brne COM2WR_Iface_RecvHandleBit_ret      ; nope, ignore
+  rcall COM2WR_Iface_StartReading          ; (R16, X)
+COM2WR_Iface_RecvHandleBit_ret:
+  ret
+; @end
+
+
+
+com2wrRecvBit:
+  ldd r16, Y+COM2WR_IFACE_OFFS_CURRBYTE
+  lsr r19                                  ; databit to carryflag
+  ror r16                                  ; carryflag to current byte
+  std Y+COM2WR_IFACE_OFFS_CURRBYTE, r16
+  ldd r17, Y+COM2WR_IFACE_OFFS_BITCOUNTER
+  dec r17
+  std Y+COM2WR_IFACE_OFFS_BITCOUNTER, r17
+  brne com2wrRecvBit_ret
+  ; byte complete, test counter for remaining bytes
+  ldd r17, Y+COM2WR_IFACE_OFFS_BUFLEFT
+  tst r17
+  breq com2wrRecvBit_overrun
+  dec r17
+  std Y+COM2WR_IFACE_OFFS_BUFLEFT, r17
+  ; store current byte
+  ldd xl, Y+COM2WR_IFACE_OFFS_BUFPOS_LO
+  ldd xh, Y+COM2WR_IFACE_OFFS_BUFPOS_HI
+  st X+, r16
+  std Y+COM2WR_IFACE_OFFS_BUFPOS_LO, xl
+  std Y+COM2WR_IFACE_OFFS_BUFPOS_HI, xh
+  ; increment byte counter, check for size, adjust remaining byte counter if msgsize received
+  ldd r18, Y+COM2WR_IFACE_OFFS_BUFUSED
+  inc r18
+  std Y+COM2WR_IFACE_OFFS_BUFUSED, r18
+  cpi r18, 2                               ; two bytes (DESTADDR, MSGLEN)?
+  brne com2wrRecvBit_ret                   ; no, jmp
+  inc r16                                  ; last recvd byte contains remaining msg size, add CRC byte
+  std Y+COM2WR_IFACE_OFFS_BUFLEFT, r16     ; set remaining bytes counter (TODO: check size!)
+  rjmp com2wrRecvBit_ret
+com2wrRecvBit_overrun:
+  ; TODO
+
+com2wrRecvBit_ret:
+  ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine com2wrResetReadBuffer
+;
+; @param Y pointer to interface data in SDRAM
+; @clobbers r16, X
+
+com2wrResetReadBuffer:
+  ldi r16, 8
+  std Y+COM2WR_IFACE_OFFS_BITCOUNTER, r16
+  clr r16
+  std Y+COM2WR_IFACE_OFFS_BUFUSED, r16
+  std Y+COM2WR_IFACE_OFFS_MODECOUNTER, r16
+  ldi xl, COM2WR_IFACE_OFFS_BUFFER
+  clr xh
+  add xl, yl
+  adc xh, yh
+  std Y+COM2WR_IFACE_OFFS_BUFPOS_LO, xl
+  std Y+COM2WR_IFACE_OFFS_BUFPOS_HI, xh
+  ldi r16, COM2WR_BUFFERSIZE
+  std Y+COM2WR_IFACE_OFFS_BUFLEFT, r16
+  ret
+; @end
+
+
+
+#endif ; AVR_MOD_COM2WROUTER_IFACE_ASM
+