Remote Processing RPC-52 - Manual (Page 17)

CHAPTER 5 RAM MEMORY
Page 15
sets disagre e, th en you m ust take action ap propr iate to
the situation.
Another technique to ch eck for v alid mem ory is
checksums. Simply writing a program to add the values
in RAM and com pare it against a number is a good
check. H owever, you cannot tell which data element
was corrupted.
Instances of data corr uption are rar e. T hey do increase
as the board power is cycled or reset. You should be
aware that data corruption is not impossible and there are
methods to detect and co rrec t it.
ASSEMBLY LANGUAGE INTERFACE
Assembly language program s must be placed in the
RPBASIC -52 EPR OM. Progr ams should start at addr ess
6 0 00 H o r h ig h er u p t o 7 F F F H .
Docum ented assem bly language interface calls listed in
the Intel MCS BASIC -52 Users Manual may w ork w ith
RPBASIC-52. T his is because RPBASIC-52 has been
reassembled and code has been shifted around.
COMMANDS
The following is a list of RPBASIC-52 commands used
w it h R A M .
Comm and Function
CALL Calls an assembly language routine
CBY Return s code m emor y data
DBY Returns or assigns internal memory
MTOP Sets top of RAM memory
PEEK B Return s a byte
PEEK W Returns a 16 bit value
PEEK $ Returns a string
POKE B Stores a by te
POKE W Stores a 16 bit value
POKE $ Stores a string
XBY Returns or assigns external memory