UP-800 (serv.man23). UP-820N, UP-820F Service Manual - Sharp ECR Service Manual (repair manual). Page 12

UP-820N/820F (V)

DIAGNOSTICS SPECIFICATIONS

5 – 2

1 Checking

For the standard SDRAM (8MB), the following checks are per-

formed. The memory contents remain unchanged before and after

the checks. 

The following processes are performed for the memory address to
be checked (0C00 0000H-0C7F FFFFH). 

In case of a compare error in comparison of the check sequence
PASS1-6, the error display is made. 

If no error occurs until the end of the last address, it is regarded as

normal completion. 

The following address check is performed furthermore. 

In case of an error, the error display is made and read/write opera-
tions at the error address are repeated without continuing the

check.

Check point address  = 0C00 0000H 0C00 0001H

0C00 0002H 0C00 0004H
0C00 0008H 0C00 0010H
0C00 0020H 0C00 0040H
0C00 0080H 0C00 0100H
0C00 0200H 0C00 0400H
0C00 0800H 0C00 1000H
0C00 2000H 0C00 4000H
0C00 8000H 0C01 0000H
0C02 0000H 0C04 0000H
0C08 0000H 0C10 0000H

2 Display

The error address and bit are displayed only when an error occurs

(They are not displayed if there is no error.)

3 How to exit the program

After displaying the check result, press the PANEL key or any key to
terminate the operation.

1 Checking

First of all, perform the presence check for the UP-S04MB2.
The memory contents remain unchanged before and after the 

check.

i. 55AAH is written into 083F FFFEH. 

ii. 083F FFFEH is read and compared with 55AAH. If the both data

are correct, go to iii. If not, “Extend RAM size : 0KB” is displayed

and the check is terminated. 

iii. AA55H is written into 087F FFFEH.

iv. 087F FFFEH is read and compared with AA55H. If both data are

correct, 083FFFFEH is read. If it is 55AAH, the model is the UP-
S08MB and the following check is performed. If it is AA55H, the

model is the UP-S04MB2 and the following check is performed.

Then, the following process is performed for the address to be

checked (UP-04MB2: 0800 0000H-083F FFFFH, UP-08MB: 0800

0000H-087F FFFFH).

In case of a compare error in comparison of the check sequence
PASS1-6, the error display is made. 

If no error occurs until the end of the last address, it is regarded as

normal completion. 

The following address check is performed in the above check

sequence.  
In case of an error, the error display is made and read/write opera-

tions at the error address are repeated without continuing the

check.
If there is no error at any check point, “Extended RAM size: 4096KB

PASS!!” (UP-S0408MN) or “Extended RAM size : 8192KB  PASS!!”

(UP-S08MB) is displayed and the check is terminated. 

Check point address:  = 0800 0000H 0800 0001H

0800 0002H 0800 0004H
0800 0008H 0800 0010H
0800 0020H 0800 0040H
0800 0080H 0800 0100H
0800 0200H 0800 0400H
0800 0800H 0800 1000H
0800 2000H 0800 4000H
0800 8000H 0801 0000H
0802 0000H 0804 0000H
0808 0000H 0810 0000H
0820 0000H

(Hereinafter, for UP-S08MB only)

0840 0000H 0840 0001H
0840 0002H 0840 0004H
0840 0008H 0840 0010H
0840 0020H 0840 0040H
0840 0080H 0840 0100H
0840 0200H 0840 0400H
0840 0800H 0840 1000H
0840 2000H 0840 4000H
0840 8000H 0841 0000H
0842 0000H 0844 0000H
0848 0000H 0850 0000H
0860 0000H

PASS1: Memory data save

PASS2: Data “0000 0000H” write

PASS3: Data “0000 0000H” read and compare,

Data “5555 5555H” write

PASS4: Data “5555 5555H” read and compare, 

Data “AAAA AAAH” write

PASS5: Data “AAAA AAAAH” read and compare

PASS6: Memory data restoration

PASS1: Memory data save

PASS2: Data “0000H” write

PASS3:   Data “0000H” read and compare,

Data “5555H” write

PASS4:   Data “5555H” read and compare,

Data “A AAAH” write

PASS5:  Data “AAAAH” read and compare

PASS6:  Memory data restoration