IP2022 User’s Manual—Instruction Set Architecture www.ubicom.com 147 FWRITE Write into Flash Memory Operation: (ADDRX || ADDRH || ADDRL) = DATAH || DATAL Bits affected: FBUSY bit in the XCFG register Opcode: 0000 0000 0001 1010 Description: This instruction writes a word of data to program
flash   memory   from   data   memory.   The   24-bit
ADDRX/ADDRH/ADDRL   register   specifies   the
address  of  a  16-bit  word  in  program  memory
which    is    loaded    with    the    contents    of    the
DATAH/DATAL  register.  If  the  address  is  not  in
program     flash     memory,     no     operation                                                                                            is
performed.  The  instruction  is  non-blocking  (i.e.
other  instructions  may  execute  before  the  write
operation is complete). After executing this instruction, the FBUSY bit in
the   XCFG   register   is   set.   When   the   write
operation is complete, the FBUSY bit goes clear.
This   instruction   must   not   be   executed   if   the
FBUSY bit is already set from a previous fread, fwrite,    or   ferase   instruction.    Program execution  out  of  flash  memory  is  not  possible
while   the   FBUSY   bit   is   set,   therefore   this