ST7066U
#" Read Busy Flag and Address
RS
0
RW DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
1
BF AC6 AC5 AC4 AC3 AC2 AC1 AC0
Code
When BF = “High”, indicates that the internal operation is being processed.So during this time the next
instruction cannot be accepted.
The address Counter (AC) stores DDRAM/CGRAM addresses, transferred from IR.
After writing into (reading from) DDRAM/CGRAM, AC is automatically increased (decreased) by 1.
#" Write Data to CGRAM or DDRAM
RS RW DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Code
1
0
D7 D6 D5 D4 D3 D2 D1 D0
Write binary 8-bit data to DDRAM/CGRAM.
The selection of RAM from DDRAM, CGRAM, is set by the previous address set instruction
: DDRAM address set, CGRAM address set. RAM set instruction can also determine the AC
direction to RAM.
After write operation, the address is automatically increased/decreased by 1, according to
the entry mode.
#" Read Data from CGRAM or DDRAM
RS RW DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Code
1
1
D7 D6 D5 D4 D3 D2 D1 D0
Read binary 8-bit data from DDRAM/CGRAM.
The selection of RAM is set by the previous address set instruction. If address set instruction of RAM is not
performed before this instruction, the data that read first is invalid, because the direction of AC is not
determined. If you read RAM data several times without RAM address set instruction before read operation,
you can get correct RAM data from the second, but the first data would be incorrect, because there is no time
margin to transfer RAM data.
In case of DDRAM read operation, cursor shift instruction plays the same role as DDRAM address
set instruction : it also transfer RAM data to output data register. After read operation address counter is
automatically increased/decreased by 1 according to the entry mode. After CGRAM read operation, display
shift may not be executed correctly.
* In case of RAM write operation, after this AC is increased/decreased by 1 like read operation. In this time,
AC indicates the next address position, but you can read only the previous data by read instruction.
V2.0
2001/03/01
21/42
POWERTIP [ POWERTIP TECHNOLOGY ]
