//----------------------------------------------------------------------
//----------------------------------------------------------------------
//S215 XCSB Standard Functions, version 7, group A        S215   08 1102
//Basic I/O Functions
//----------------------------------------------------------------------
//----------------------------------------------------------------------
proc ubyte	GetInBts()

if g_mode == 0 then
  gx = PORTA
else
  gx = PORTB
endif

if g_polarity == 0 then
  return gx
endif

if g_polarity == 1 then
  return gx ^ 0xff	//Invert bits because of negative input logic 
endif

endproc

//----------------------------------------------------------------------
proc ubyte 	SelBit(ubyte ibyt, ubyte bitno)

gx = 1 << bitno		//Prepare mask
gy = ibyt & gx		//Mask off all except for desired bit
gy = gy >> bitno		//Shift bit into bit 0
return gy
endproc

//----------------------------------------------------------------------
proc 		Outall(ubyte outbyte)
g_obyt = outbyte

if g_polarity == 0 then
  gx = outbyte
else
  gx = outbyte ^ 0xff
endif

if g_mode == 0 then
  PORTB = gx 
else
  PORTA = gx 
endif

endproc
//----------------------------------------------------------------------
proc 		Outallopp(ubyte outbyte)
//Same as Outall( ), except output port is opposite of what "g_mode" indicates
g_opobyt = outbyte

if g_polarity == 0 then
  gx = outbyte
else
  gx = outbyte ^ 0xff
endif

if g_mode == 0 then
  PORTA = gx 
else
  PORTB = gx 
endif

endproc
//----------------------------------------------------------------------
proc 		Ob(ubyte bitvalue, ubyte bitno, ubyte f_print)

gx = 1
gx = gx << bitno
gy = bitvalue<<bitno
g_obyt = g_obyt & ~gx	//Make a hole for the bit
g_obyt = g_obyt | gy 	//Insert the bit
if (f_print == 1) then
  Outall(g_obyt)
endif
endproc
//----------------------------------------------------------------------
proc 		Obopp(ubyte bitvalue, ubyte bitno, ubyte f_print)
//Same as Ob( ), except port used is opposite that indicated by "g_mode"

gx = 1
gx = gx << bitno
gy = bitvalue<<bitno
g_obyt = g_obyt & ~gx	//Make a hole for the bit
g_obyt = g_obyt | gy 	//Insert the bit
if (f_print == 1) then
   Outallopp(g_obyt)
endif
endproc
//----------------------------------------------------------------------
proc		Initp(ubyte mode, ubyte polarity)
//Mode:
//0 Port A is all inputs, port B is all outputs
//1 Port A is all outputs, port B is all inputs

// Polarity:
// 0  I/O bits not inverted
// 1  I/O bits inverted

g_mode =mode
g_polarity = polarity

if mode == 0 then 
  TRISA = 0xff	//All lines are for inputting
  TRISB = 0	//All lines are for outputting
endif
if mode == 1 then
  TRISA = 0	//All lines are for outputting
  TRISB = 0xff	//All lines are for inputting
endif

g_obyt = 0

endproc
//----------------------------------------------------------------------

proc ubyte Gib(ubyte bitno)
  gy = GetInBts()
  gx = SelBit(gy, bitno)
  return gx
endproc

//-----------------------------