avr: added routine Util_WaitForPinState1ms

avr/common/utils_wait_pin.asm

@@ -0,0 +1,54 @@
+; ***************************************************************************
+; copyright   : (C) 2023 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.   *
+; ***************************************************************************
+
+
+; ***************************************************************************
+; code
+
+
+.cseg
+
+
+
+; ---------------------------------------------------------------------------
+; Util_WaitForPinState1ms
+;
+; Waits up to 1ms for status change on a pin
+;
+; @param R16 state to wait for (00 for low, 0xff for high)
+; @param R17 io address of the port containing the pin
+; @param R18 pin mask
+; @return CFLAG set if state reached, cleared otherwise
+; REGS: R19, R22
+
+Util_WaitForPinState1ms:
+  push xl
+    push xh
+      clr xh
+      mov xl, r17
+      ldi r19, 200
+com2WaitForDataState1ms_loop:
+        ld r22, X
+        eor r22, r16
+        andi r22, r18
+        breq com2WaitForDataState1ms_stateReached
+        Utils_WaitNanoSecs 5000, 0, r22                ; wait for 5us
+        dec r19
+      brne com2WaitForDataState1ms_loop
+      clc
+      rjmp com2WaitForDataState1ms_ret
+com2WaitForDataState1ms_stateReached:
+      sec
+com2WaitForDataState1ms_ret:
+    pop xh
+  pop xl
+  ret
+
+
+