# Helper for common memory read/modify/write procedures
# mrw: "memory read word", returns value of $reg
proc mrw {reg} {
set value ""
mem2array value 32 $reg 1
return $value(0)
}
add_usage_text mrw "address"
add_help_text mrw "Returns value of word in memory."
proc mrb {reg} {
set value ""
mem2array value 8 $reg 1
return $value(0)
}
add_usage_text mrb "address"
add_help_text mrb "Returns value of byte in memory."
# mmw: "memory modify word", updates value of $reg
# $reg <== ((value & ~$clearbits) | $setbits)
proc mmw {reg setbits clearbits} {
set old [mrw $reg]
set new [expr ($old & ~$clearbits) | $setbits]
mww $reg $new
}
add_usage_text mmw "address setbits clearbits"
add_help_text mmw "Modify word in memory. new_val = (old_val & ~clearbits) | setbits;"
