ST7920
Instruction set 2: (RE=1: extended instruction)
Code
Exec time
(540KHZ)
Inst.
Description
RS RW DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
Enter standby mode, any other instruction can terminate.
Standby
0
0
0
0
0
0
0
0
0
0
0
1
72 us
COM1…32 are halted.
Scroll or
RAM
SR=1: enable vertical scroll position
0
0
0
0
0
0
1
SR
72 us
Address.
Select
SR=0: enable CGRAM address (basic instruction)
Select 1 out of 4 line (in DDRAM) and decide whether to
Reverse
(by line)
0
0
0
0
0
0
0
0
1
0
0
1
R1 R0 reverse the display by toggling this instruction
R1,R0 initial value is 0,0
72 us
72 us
DL=1 :8-bit interface
DL=0 :4-bit interface
Extended
Function
Set
1
RE=1: extended instruction set
0
1
DL
X
G
0
RE
RE=0: basic instruction set
G=1 :graphic display ON
G=0 :graphic display OFF
Set Scroll
Address
0
0
0
0
0
1
AC5 AC4 AC3 AC2 AC1 AC0 SR=1: AC5~AC0 the address of vertical scroll
Set GDRAM address to address counter (AC)
72 us
72 us
Set Graphic
Display
Set the vertical address first and followed the horizontal
address by consecutive writings
0
0
0
0
AC3 AC2 AC1 AC0
RAM
AC5 AC4 AC3 AC2 AC1 AC0
Vertical address range: AC5…AC0
Address
Horizontal address range: AC3…AC0
Note:
1. Make sure that ST7920 is not in busy state by reading the busy flag before sending instruction or data. If using delay loop instead, please
make sure the delay time is enough. Please refer to the instruction execution time.
2. “RE” is the selection bit of basic and extended instruction set. After setting the RE bit, the value will be kept. So that the software doesn’t
have to set RE every time when using the same instruction set.
V4.0
17/49
2008/08/18
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
