ks0070b Samsung Semiconductor, Inc., ks0070b Datasheet - Page 11

• Manufacturer Part Number: ks0070b
• Description: 16com / 80seg Driver & Controller For Dot Matrix Lcd
• Manufacturer: Samsung Semiconductor, Inc.

KS0070B
FUNCTION DESCRIPTION
System Interface
This chip has both kinds of interface type with MPU: 4-bit bus and 8-bit bus.
4-bit bus and 8-bit bus are selected by the DL bit in the instruction register.
During read or write operation, two 8-bit registers are used. One is the data register (DR), and the other is the
instruction register (IR).
The data register (DR) is used as a temporary data storage place for being written into or read from DDRAM/
CGRAM. Target RAM is selected by RAM address setting instruction. Each internal operation, reading from or writ-
ing into RAM, is done automatically.
After MPU reads DR data, the data in the next DDRAM/CGRAM address is transferred into DR automatically.
Also, after MPU writes data to DR, the data in DR is transferred into DDRAM/CGRAM
automatically.
The Instruction register (IR) is used only to store instruction codes transferred from MPU. MPU cannot use it to
read instruction data.
To select a register, use RS input pin in 4-bit/8-bit bus mode.
Table 1. Various Kinds of Operations According to RS and R/W bits.
Busy Flag (BF)
When BF = "1", 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 = "0" and R/W = "1"
(Read Instruction Operation), through DB7 port.
Before executing the next instruction, be sure that BF is not "1".
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)
16COM / 80SEG DRIVER & CONTROLLER FOR DOT MATRIX LCD
Operation