ks0078 Samsung Semiconductor, Inc., ks0078 Datasheet - Page 9

• Manufacturer Part Number: ks0078
• Description: 34com/120seg Driver & Controller For Dot Matrix Lcd
• Manufacturer: Samsung Semiconductor, Inc.

KS0078
FUNCTION DESCRIPTION
System Interface
This chip has all three kinds interface type with MPU : serial, 4-bit bus and 8-bit bus. Serial and bus(4-bit/8-bit) is selected by
IM input, and 4-bit bus and 8-bit bus is selected by DL bit in the instruction register.
During read or write operation, two 8-bit registers are used. one is data register (DR), the other is instruction register(IR).
The data register(DR) is used as temporary data storage place for being written into or read from DDRAM/CGRAM/SEGRAM,
target RAM is selected by RAM address setting instruction. Each internal operation, reading from or writing into RAM, is done
automatically.
Hence, after MPU reads DR data, the data in the next DDRAM/CGRAM/SEGRAM address is transferred into DR
automatically. Also after MPU writes data to DR, the data in DR is transferred into DDRAM/CGRAM/SEGRAM automatically.
The Instruction register(IR) is used only to store instruction code transferred from MPU. MPU cannot use it to read instruction
data.
To select register, use RS/CS input pin in 4-bit/8-bit bus mode(IM = "High") or RS bit in serial mode(IM = "Low").
Table 2. Various kinds of operations according to RS and R/W bits.
Busy Flag (BF)
When BF = "High", it indicates that the internal operation is being processed. So during this time the next instruction cannot
be accepted. BF can be read, when RS = Low and R/W = High(Read Instruction Operation), through DB7 port.
Before executing the next instruction, be sure that BF is not High.






























RS
0
0
1
1
R/W
0
1
0
1
Instruction Write operation (MPU writes Instruction code into IR)
Read Busy flag(DB7) and address counter (DB0 ~ DB6)
Data Write operation (MPU writes data into DR)
Data Read operation (MPU reads data from DR)
34COM/120SEG DRIVER & CONTROLLER FOR DOT MATRIX LCD



















































Operation