In SX Microcontrollers, SX/B Compiler and SX-Key Tool, JonnyMac wrote:

As and idea... you could rename the nibble write routines and create complimentary read routines.  For example:

[code]' Use: bResult = RD_NIB_LO value
' -- returns low nibble of value

FUNC RD_NIB_LO
  ASM
    AND   __param1, $0F                         ' clear high nibble
  ENDASM
  ENDFUNC


' Use: bResult = RD_NIB_HI value
' -- returns high nibble of value

FUNC RD_NIB_LO
  ASM
    AND   __param1, $F0                         ' clear low nibble
    SWAP  __param1
  ENDASM
  ENDFUNC


' Use: bResult = WR_NIB_LO target, value
' -- moves value into low nibble of target
' -- value truncated to four bits

FUNC WR_NIB_LO
  ASM
    AND   __param1, #$F0                        ' clear low nib
    AND   __param2, #$0F                        ' truncate to 4 bits
    OR    __param1, __param2                    ' merge the nibbles
  ENDASM
  ENDFUNC


' Use: bResult = NIB_HI target, value
' -- moves value into high nibble of target
' -- value truncated to four bits

FUNC WR_NIB_HI
  ASM
    AND   __param1, #$0F                        ' clear high nib
    AND   __param2, #$0F                        ' truncate to 4 bits
    SWAP  __param2                              ' move value to high nib
    OR    __param1, __param2                    ' merge
  ENDASM
  ENDFUNC


' Use: bResult = MERGE value1, value2
' -- merge two 4-bit values into a byte
' -- value1 to high nibble, value2 to low nibble
' -- values truncated to four bits

FUNC MERGE
  ASM
    AND   __param1, #$0F                        ' truncate to 4 bits
    SWAP  __param1                              ' move to high nibble
    AND   __param2, #$0F                        ' truncate to 4 bits
    OR    __param1, __param2                    ' merge
  ENDASM
  ENDFUNC[/code]

Now you could do something like this to scroll the digits left (blanking the right-most display element):

[code]SUB DISPLAY_LEFT
  SWAP hrs                              ' move 1s to 10s position
  tmpB1 = RD_NIB_HI mins                ' get 10s from next section
  hrs = WR_NIB_LO tmpB1
  SWAP mins
  tmpB1 = RD_NIB_HI secs
  secs = WR_NIB_LOW tmpB1
  SWAP secs
  secs = WR_NIB_LOW $F                  ' blanking value
  ENDSUB[/code]

Note that this is not designed to be cute or clever (i.e., optimized), it is meant to be obvious and easy.  Running this routine six times with a delay in between will scroll the time off.  Now... if you want the seconds to be updating during the scrolling, well, that's going to take some more work.  Try this first, then move on to that if it is a requirement.

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=408151#m410027

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2009 (http://www.dotNetBB.com)