20T202DA1J Pacer Components, 20T202DA1J Datasheet - Page 12

• Manufacturer Part Number: 20T202DA1J
• Description: Vacuum Fluorescent Display Module
• Manufacturer: Pacer Components

2X20 LCD Compatible VFD Module
6. INSTRUCTIONS
6.1 Outline
Only the instruction register (IR) and the data register (DR) of the VFD controller can be controlled by the user's MPU.
Before starting the internal operation of the controller, control information is temporarily stored into these registers to
allow different data transfer mode, display line setting and dimming control etc. The internal operation of the controller
is determined by signals sent from the MPU. These signals, which include register selection signal (RS), write enable
signal (E), and the data bus (DB4 to DB7), make up the controller instructions.
There are four categories of instructions which are:
Normally, instructions that perform data transfer with internal RAM are used the most.
However, auto-incrementation by 1 (or auto-decrementation by 1) of internal RAM addresses after each data write can
lighten the program load of the MPU. Since the display shift instruction can perform concurrently with display data
write, the user can minimize system development time with maximum programming efficiency.
*Instruction List
Display Clear
Cursor Home
Entry Mode Set
Display ON/OFF Control
Cursor or Display Shift
Function Set
CG-RAM Address Set
DD-RAM Address Set
Data Writing to CG- or
DD-RAM
REMARKS:
* DD-RAM: Display
* CG-RAM: Character
* ACG: CG-RAM
* ADD: DD-RAM
* ACC: Address Counter
Data RAM
Generator RAM
Address
Address
* Designate controller functions, such as display format, data length, etc.
* Set internal RAM addresses.
* Perform data transfer with internal RAM.
* Perform miscellaneous functions.
Instructions
* I/D = 1: Increment
* I/D = 0: Decrement
* S = 1: Display Shift Enabled
* S = 0: Cursor Shift Enabled
* S/C = 1: Display Shift
* S/C = 0: Cursor Move
* R/L = 1: Shift to the Right
* R/L = 0: Shift to the Left
RS
0
0
0
0
0
1
1
0
0
D7
0
0
0
0
0
1
0
0
D6
0
0
0
0
0
0
1
ADD (DD-RAM Address)
D5
0
0
0
0
0
1
Instruction Code
Character Code
ACG (CG-RAM Address)
20T202DA1J (Rev. 3.0)
D4
IF
0
0
0
0
1
Page - 12 of 17
S/C R/L
D3
N
0
0
0
1
D2
D
0
0
1
*
BR1 BR0
I/D
D1
C
0
1
*
D0
B
1
*
S
*
Clears all display and sets DD-RAM address 00
in address counter.
Sets DD-RAM address 0 in ACC. Also returns
the display being shifted to the original position.
DD-RAM contents remain unchanged.
Sets the cursor direction and specifies display
shift. These operations are performed during
writing/reading data.
Sets all display ON/OFF (D), cursor ON/OFF (C),
cursor blink of character position (B).
Shifts display or cursor, keeping DD-RAM
contents.
Sets data length (IF), number of display lines (N),
Set brightness level (BR1,BR0)
Sets the CG-RAM address.
Sets the DD-RAM address.
Writes data into CG-RAM or DD-RAM.
* IF = 1: 8-bit Operation
* IF = 0: 4-bit Operation
* N = 1: 2 Lines Display
* N = 0: 1 Line Display
* BR1, BR0 =
00: 100%, 01: 75%, 10: 50%, 11: 25%
Descriptions