Service manual

Service Manual
*PAddex
Exercise a specified memory location
Syntax
*PAddex [-BM] <addr>
*PAddex [-BM] <addr> <addr>
*PAddex [-BCM] -W <addr> <addr> <data>
*PAddex [-BM] -W <addr> <addr> <data>
<data>
Use
This command is intended to generate various
cycling patterns to assist in debugging address
decodes, memory failures etc.
The single-address form generates repeated reads of
memory at the given location. If the M option is given,
the LDMIA instruction is used to read two consecutive
word locations. If the B option is given, byte reads are
performed. If two addresses are given, pairs of read
cycles alternating between the two addresses are
performed.
The W option causes data to be written to the
location before reading back: the data written to the
address or pair of addresses will be <data> unless
the C option is used to write <data> and it's
complement or unless a second <data> argument is
given. The M option
will cause STMIA and LDMIA to be used for the
operation.
The repetitive operation may be halted with the Esc
key.
Example
*PAddex -m 2000000
Repetitively read address &2000000 and &2000004
using sequential memory accesses.
Related Commands
`PMemory, *PMemoryA, *PDatex
*PDatex
Exercise the data bus at a given address
Syntax
*PDatex [-BCM]
*PDatex [-BCM] <address>
*PDatex [-BCM] <address> <data>
*PDatex [-BM] <address> <data> <data>
Use
This command is very similar to PAddex, and is
intended to generate various cycling data values to
assist in finding data bus open and short circuits.
The command with no arguments performs repetitive
writes (of the value &55555555) and reads at address
&200000. The B option causes a byte to be written,
the M option uses the STMIA / LDMIA to perform
consecutive memory cycles at adjacent addresses
and the C option causes alternate true and
complemented data to be written.
An address may be given to generate the bus cycles
at an alternate address and data arguments may be
given to specify the data written there.
The repetitive operation may be halted with the Esc
key.
Example
*PDatex -b 2400000 32
Repetitively write (and read back) the byte value 32
to the lowest address used by a second MEMC in a
multiple MEMC system.
Related Commands
`PMemory, *PMemoryA, *PAddex
Part 5 - Main PCB fault diagnosis Issue 2, June 1991 5-13