Er-03Mb Check; Er-04Mb Check - Sharp ER-A750 Service Manual

3) ER-03MB Check

1 Check content
The ER-03MB presence check is performed in the following pro-
cedure. The memory contents will not be changed by this check.
•
55AAH is written into 2FFFFEH.
•
2FFFFEH is read and compared with 55AAH. If the both data
are correct, the following procedure is performed. If not, "Ex-
tended RAM size: 0KB" is displayed and the check is ter-
minated.
•
55AAH is written into 3FFFFEH.
•
3FFFFEH is read and compared with 55AAH. If the both data
are not correct, the following procedure is performed. If correct,
"Extend RAM is : ER-04MB" is displayed and the check is
terminated.
For the ER-03MB, the following check is performed.
The following processes are performed for the check address
(200000H 2FFFFFH).
PASS1: Memory data save
PASS2: Data "0000H" write
PASS3: Data "0000H" read/compare, data "5555H" write
PASS4: Data "5555H" read/compare, data "AAAAH" write
PASS5: Data "AAAAH" read/compare
PASS6: Memory data writed the saved data
In case of a compare error in the check sequences of PASS1
PASS6, an error display is made. If there is no error at all, the
check is normally terminated.
In addition, the following address check is performed in the above
check sequence.
In case of an error, an error display is made and read/write of the
address where the error occurred is repeated.
Check point address = 200000H, 200001H
200002H, 200004H
200008H, 200010H
200020H, 200040H
200080H, 200100H
200200H, 200400H
200800H, 201000H
202000H, 204000H
208000H, 210000H
220000H, 240000H
280000H
2 Display
ER-03MB Check
Extended RAM size : 1024KB
OR!!)
Error Address xxxxxxH
Write Data
Read Data
The error address and the bit are displayed only when the error
occurs. (If the error does not occur, they are not displayed.)
3 Terminating procedure
After completion of check, press the CANCEL key.
PASS!!(or ERR
xxxxH
xxxxH

4) ER-04MB Check

1 Check content
The ER-04MB presence check is performed in the following pro-
cedure. The memory contents must not be changed by this check.
•
55AAH is written into 3FFFFEH.
•
3FFFFEH is read and compared with 55AAH. If the both data
are correct, the following procedure is performed. If not, go to
????????.
•
55AAH is written into 2FFFFEH.
•
2FFFFEH is read and compared with 55AAH. If the both data
are correct, "Extend RAM is : ER-03MB" is displayed and the
check is terminated. If not, "Extended RAM size : 0KB" is dis-
played and the check is terminated.
For the ER-04MB, the following check is performed.
The following processes are performed for the check address
(200000H 3FFFFFH).
PASS1: Memory data save
PASS2: Data "0000H" write
PASS3: Data "0000H" read/compare, data "5555H" write
PASS4: Data "5555H" read/compare, data "AAAAH" write
PASS5: Data "AAAAH" read/compare
PASS6: Memory data writed the saved data
In case of a compare error in the check sequences of PASS1
PASS6, an error display is made. If there is no error at all, the
check is normally terminated.
In addition, the following address check is performed in the above
check sequence.
In case of an error, an error display is made and read/write of the
address where the error occurred is repeated without performing
the check.
Check point address = 200000H, 200001H
2 Display
ER-04MB Check
Extended RAM size : 2048KB
OR!!)
Error Address
Write Data
Read Data
The error address and the bit are displayed only when the error
occurs. (If the error does not occur, they are not displayed.)
3 Terminating procedure
After completion of check, press the CANCEL key.
6 – 3
200002H, 200004H
200008H, 200010H
200020H, 200040H
200080H, 200100H
200200H, 200400H
200800H, 201000H
202000H, 204000H
208000H, 210000H
220000H, 240000H
280000H, 300000H
PASS!!(or ERR
xxxxxxH
xxxxH
xxxxH