tcl/mem_helper.tcl

   1 # Helper for common memory read/modify/write procedures
   2
   3 # mrw: "memory read word", returns value of $reg
   4 proc mrw {reg} {
   5         set value ""
   6         mem2array value 32 $reg 1
   7         return $value(0)
   8 }
   9
  10 add_usage_text mrw "address"
  11 add_help_text mrw "Returns value of word in memory."
  12
  13 # mrh: "memory read halfword", returns value of $reg
  14 proc mrh {reg} {
  15         set value ""
  16         mem2array value 16 $reg 1
  17         return $value(0)
  18 }
  19
  20 add_usage_text mrh "address"
  21 add_help_text mrh "Returns value of halfword in memory."
  22
  23 # mrb: "memory read byte", returns value of $reg
  24 proc mrb {reg} {
  25         set value ""
  26         mem2array value 8 $reg 1
  27         return $value(0)
  28 }
  29
  30 add_usage_text mrb "address"
  31 add_help_text mrb "Returns value of byte in memory."
  32
  33 # mmw: "memory modify word", updates value of $reg
  34 #       $reg <== ((value & ~$clearbits) | $setbits)
  35 proc mmw {reg setbits clearbits} {
  36         set old [mrw $reg]
  37         set new [expr ($old & ~$clearbits) | $setbits]
  38         mww $reg $new
  39 }
  40
  41 add_usage_text mmw "address setbits clearbits"
  42 add_help_text mmw "Modify word in memory. new_val = (old_val & ~clearbits) | setbits;"