ST7920
Testing Step:
1. Clear whole DDRAM area by writing data 0x00.
2. Composing TT1 and TT2 to make the ‘Reset’ action, and clear the internal counter.
3. Selecting the test mode by setting TT1 and TT2 (CGROM or HCGROM).
4. After setp1 and setp2, entering some impulse signals through Pin4 (CLK).
5. Reading the CHECK SUM data through D0 to D7.
6. Comparing CHECK SUM with the Code Table (upper table) to check if the data is correct or not.
TT1
1
TT2
1
No. of counts
--
Status
RESET
0
1
1
0
655362
10242
CGROM
HGROM
Test process flow:
V4.0
30/49
2008/08/18