APPLICATION NOTE

AN-E-2211D
APPLICATION NOTE
VACUUM FLUORESCENT DISPLAY MODULE
CHARACTER DISPLAY MODULE
M204SD01AA
GENERAL DESCRIPTION
Futaba Vacuum Fluorescent Display Module M204SD01AA, with
Futaba VFD 204-SD-01G display, produces 20 digits on 4 rows.
Each character is displayed in 5×7 dot matrix.
Consisting of a VFD, microcomputer, driver IC, the module can be
connected directly to the system bus easily, thus simplifying interfacing.
The bright and aesthetically pleasing VFD makes the module desirable
for an application in office equipments, such as computer terminals,
measuring equipment, etc.

!
Important Safety Notice
Please read this note carefully before using the product.
Warning
• The module should be disconnected from the power supply before handling.
• The power supply should be switched off before connecting or disconnecting the
power or interface cables.
• The module contains electronic components that generate high voltages which may
cause an electrical shock when touched.
• Do not touch the electronic components of the module with any metal objects.
• The VFD used on the module is made of glass and should be handled with care. When
handling the VFD, it is recommended that cotton gloves be used.
• The module is equipped with a circuit protection fuse.
• Under no circumstances should the module be modified or repaired.
Any unauthorized modifications or repairs will invalidate the product warranty.
• The module should be abolished as the factory waste.
AN-E-2211D [Important Safety Notice]

CONTENTS
Page
1. FEATURES 1
2. GENERAL SPECIFICATIONS
2-1. DIMENSIONS, WEIGHT 2
2-2. SPECIFICATIONS OF THE DISPLAY PANEL 2
2-3. ENVIRONMENT CONDITIONS 2
2-4. ABSOLUTE MAXIMUM RATINGS 2
2-5. RECOMMENDED OPERATING CONDITIONS 3
2-6. ELECTRICAL CHARACTERISTICS 3
3. FUNCTION
3-1. DATA AND CONTROL CODE WRITE-IN 4
3-2. CONTROL CODE 4∼7
3-3. SELF-TEST 7
3-4. POWER ON RESET 7
3-5. SELECTION OF INPUT MODE 7
4. INTERFACE CONNECTION
4-1. CONNECTOR PIN CONNECTION 8
4-2. WRITE-IN TIMING 8∼9
FIGURE-1 MECHANICAL DRAWING 10
FIGURE-2 CIRCUIT BLOCK DIAGRAM 11
FIGURE-3 DISPLAY CHARACTER CODE 12
5. WARRANTY 13
6. OPERATING RECOMMENDATIONS 13
AN-E-2211D [CONTENTS]

1. FEATURES
1-1. Using an one chip micro computer, the module can be connected to the system bus directly.
1-2. Two hundred sixteen different characters consisting of alpha-numeric and other symbols can
be displayed.
1-3. Since a DC/DC converter is included, only a 5V power source is required to operate the
module.
1-4. High quality and reliability, also long life can be achieved with FUTABA VFD.
1-5. Either parallel or serial mode can be selected as the data input form.
1-6. The module is small, light and thin mechanical sizing allows for maximum reliability.
1-7. The module’s surface mount components allow for maximum reliability.
1-8. The module has up three definable characters, they can be displayed as original fonts.
1-9. Four levels of brightness control is available.
AN-E-2211D [1/13]

2. GENERAL SPECIFICATIONS
2-1. DIMENSIONS, WEIGHT (Refer FIGURE-1)
Table-1
Item Specification Unit
(L) 135.0 ± 1
Outer
(W) 70.0 ± 1
Dimensions
(T) 31 Max.
mm
Weight Approx. 145 g
2-2. SPECIFICATION OF THE DISPLAY PANEL
Table-2
Item Specification Unit
Display Area 33.2×89.65 mm
The Number of Digits 20 digits (5×7dots)× 4 rows −
Dot Pitch (H×W) 0.75×0.69 mm
Dot Size (H×W) 0.5×0.44 mm
Character Size(H×W) 5.0×3.2 mm
Character Pitch (H×W) 9.4×4.55 mm
Color of Illumination Green (λp=505nm) −
Note) By using a filter, uniform color ranging from blue to orange (including white)
can be obtained.
2-3. ENVIRONMENT CONDITIONS
Table-3
Item Symbol Min. Max. Unit
Operating Temperature Topr -20 +70 °C
Storage Temperature Tstg -20 +70 °C
Operating Humidity (Note) Hopr 20 85 %
Storage Humidity (Note) Hstg 20 90 %
Vibration (10 to 55 Hz) − − 4 G
Shock − − 40 G
Note) Avoid operations and/or storage in moist environmental conditions.
2-4. ABSOLUTE MAXIMUM RATINGS
Table-4
Item Symbol Min. Max. Unit
Supply Voltage Vcc -0.3 7.0 V
Input Signal Voltage V IS -0.3 7.0 V
AN-E-2211D [2/13]

2-5. RECOMMENDED OPERATING CONDITIONS
Table-5
Item Symbol Condition Min. Typ. Max. Unit
Supply Voltage Vcc − 4.5 5.0 5.5 V
H-Level Input Voltage V IH Vcc=5V 2.0 − − V
L-Level Input Voltage V IL Vcc=5V − − 0.8 V
2-6. ELECTRICAL CHARACTERISTICS
Table-6
Item Symbol Condition Min. Typ. Max. Unit
Supply Current I cc − 0.75 1 A
Vcc=5.0V
Power Consumption − − 3.75 − W
(All on)
Luminance
L
340 690 − cd/m 2
H-Level Input Current I IH V IH =2.0V − − 20 µA
L-Level Input Current I IL V IL =0.8V − − -0.4 mA
Vcc=5V
H-Level Output Voltage V OH
I OH =-1.0mA
4.0 − − V
Vcc=5V
L-Level Output Voltage V OL
I OL =4.0mA
− − 0.45 V
Note) The surge current can be approx.3 times the specified maximum supply current at power on,
except peaked charge current to a capacitor.
AN-E-2211D [3/13]

3. FUNCTIONS
The module has the functions such as data and control code write, SELF-TEST, and power-on
reset function. (See Table-7)
Table-7
TEST SEL WR RXD Function
Parallel and Serial
interface
L X X X Self test
Parallel interface H or NC L ↑ NC Data and control code write in
Serial interface H or NC NC NC * Data and control code write in
L : Low level (0V)
H : High level (5V)
X : Low or High level
NC : Non connection
↑ : Low to high transition
* : RXD (Serial input)
Table-7 THE BASIC FUNCTION
3-1. DATA AND CONTROL CODE WRITE IN
When the data is being written in, the BUSY signal is active which indicates that the module
is processing data.
(When data is under processing, the BUSY signal is high “H”.)
In case of parallel input, data or control command is to be written at the low-to high
transition of WR (L→H), when SEL = low “L”, and TEST = high “H”.
The display character from follows equivalent to JIS-6220 (Alphabets Katakanas and
Symbols etc.).
After a character is written in, the write-in position will be shifted to the right one digit
automatically.
The above action can be executed, only when the BUSY signal is low “L”.
3-2. CONTROL CODE
The control codes are available as follows.
The details will be explained on the next page.
(1) DEF : Define Characters UF0∼2 : (03 HEX)
(2) DIM : Dimming : (04 HEX)
(3) BS : Back Space : (08 HEX)
(4) HT : Horizontal Tab : (09 HEX)
(5) LF : Line Feed : (0A HEX)
(6) CR : Carriage Return : (0D HEX)
(7) DP : Display Position : (10 HEX)
(8) DC1 : Normal Display Mode : (11 HEX)
(9) DC2 : Vertical Scroll Mode : (12 HEX)
(10) RST : Reset : (1F HEX)
AN-E-2211D [4/13]

(1) DEF (Define UF 0∼2) :
The DEF command defines user definable characters UF 0∼2.(up to 3 fonts)
These fonts are stored in the module according to the following command are data sequence.
1 byte
DEF command code
(03H)
+
1 byte
Position code
(CDH∼CFH)
+
5 bytes
the font data
1-1 2-1 3-1 4-1 5-1 Bit
1-2 2-2 3-2 4-2 5-2 7 6 5 4 3 2 1 0
1-3 2-3 3-3 4-3 5-3 1st 1-1 2-1 3-1 4-1 5-1 1-2 2-2 3-2
1-4 2-4 3-4 4-4 5-4 2nd 4-2 5-2 1-3 2-3 3-3 4-3 5-3 1-4
1-5 2-5 3-5 4-5 5-5 Byte 3rd 2-4 3-4 4-4 5-4 1-5 2-5 3-5 4-5
1-6 2-6 3-6 4-6 5-6 4th 5-5 1-6 2-6 3-6 4-6 5-6 1-7 2-7
1-7 2-7 3-7 4-7 5-7 5th 3-7 4-7 5-7 “L” “L” “L” “L” “L”
(a) Character Font
(b) Font Data
Example of write-in character “1” in UF 0.
Control and data strings 03H, CDH, 23H, 08H, 42H, 11H, C0H.
Bit
7 6 5 4 3 2 1 0
1st L L H L L L H H
2nd L L L L H L L L
Byte 3rd L H L L L L H L
4th L L L H L L L H
5th H H L L L L L L
(a) Character (b) Font Data “H” : Turn On
“L” : Turn Off
Fig.1 Defining User’s Font
(2) DIM (Dimming) :
The brightness can be controlled into four levels by using this function.
After writing 04H, another byte mentioned under is written to change the brightness out put.
1 byte
(DIM command code), 04H + 1 byte
Dimming level data
Dimming Level
100 %
60 %
40 %
20 %
Table-8
Data
FFH
60H
40H
20H
AN-E-2211D [5/13]

(3) BS (Back Space) :
The write-in position is shifted to the left one digit.
When the write-in position is on the most significant digit of the third row, the write-in
position moves to the least significant digit of the second row.
When the write-in position is on the most significant digit of the first row, the write-in
position moves to the least significant digit of the fourth row.
(4) HT (Horizontal Tab) :
The write-in position is shifted to the right one digit.
When the write-in position is on the least significant digit of the first row, the write-in position
will move to the most significant digit of the second row.
When the write-in position is on the least significant digit of the second row, the writ-in
position will move to the most significant digit of the first row.
(5) LF (Line Feed) :
When the write-in position is in the fourth row, the character displayed second to fourth row,
is shifted up, leaving the write-in position at its present position, then the fourth row is
cleared.
When the write-in position is in first to third row, the write-in position moves down to under
row staying on the same line.
(6) CR (Carriage Return) :
The write-in position moves to the most significant digit of the same row.
(7) DP (Display Position) :
Instead of writing the character from the first digit, the write-in starting position can be
pointed by using this function.
After writing 10 HEX to prepare module for this command, another HEX byte is written to
specify the position desired.
A third byte representing data is then sent.
The most significant digit The least significant
1st row 00 HEX 13 HEX
2nd row 14 HEX 27 HEX
3rd row 28 HEX 3B HEX
4th row 3C HEX 4F HEX
(8) DC1 (Normal Display Mode) :
After writing a character, the write-in position is shifted to the right one digit automatically.
When the write-in position is on the least significant digit of the first to third row, the write-in
position moves to the significant digit of the under row.
When the character is displayed on the least significant digit of the fourth row, the write-in
position is on the same digit.
And the character code is written in the module next, first, all digits are cleared, second, the
character is displayed on the most significant digit of the first row and the write-in position
moves to the next digit.
When the power is turn on, this DC1 Mode is selected, and will be held until another mode is
selected.
AN-E-2211D [6/13]

(9) DC2 (Vertical Scroll Mode) :
After writing the character up to the least significant digit of the fourth row, all the characters
displayed in the second to fourth row are shifted to the upper row, clearing the fourth row.
(10) RST (Reset) :
Resetting the module.
All the characters displayed are, then the write-in position is on the most significant digit of
the first row.
The displaying status is the same as the hardware Reset, but the font data of UF 0∼2 is kept.
The display mode is set for DC1.
3-3. SELF-TEST
When the TEST terminal is kept into “L” (connector pin #16 to be connected to GND.) the
SELF-TEST starts.
Then the display shows characters, Alphabets, and symbols, in that order. Eighty (4×20)
characters are displayed at a time.
Using this mode, neither data write-in nor control code write-in is allowed.
To release this mode, TEST must be set to “H”.
3-4. POWER ON RESET
When the module is turned, the display and the memory are cleared and the module is
initialized.
The display mode is set for 100%.
3-5. SELECTION OF INPUT MODE
Table-9 shows the combinations of the signal lines for the parallel or serial input.
Users must choose of the combinations.
Unused signal lines are to open (internally pulled up).
• Serial Input
Baud rate is selected by J1∼J3.
J1
J2 Baud rate select
J3
J3
Table-9
J1 Short Open Short Open
J2 Short Short Open Open
Short 1200 (bps) 2400 4800 9600
Open 7812.5 15625 31250 62500
Note) When the module is shipped, J1, J2 and J3 are open.
Table-9 BAUD RATE SELECTION
AN-E-2211D [7/13]

4. INTERFACE CONNECTION
4-1. CONNECTOR PIN CONNECTION
Connector : A1-20PA-2.54DSA (HIROSE) or equivalent
Socket : HIF3B-20D-2.54R (HIROSE) or equivalent
Table-10
Pin No. Signal Serial In Parallel In Pin No. Signal Serial In Parallel In
1 D7 NC ◦ 2 5V ◦ ◦
3 D6 NC ◦ 4 5V ◦ ◦
5 D5 NC ◦ 6 5V ◦ ◦
7 D4 NC ◦ 8 GND ◦ ◦
9 D3 NC ◦ 10 GND ◦ ◦
11 D2 NC ◦ 12 GND ◦ ◦
13 D1 NC ◦ 14 GND ◦ ◦
15 D0 NC ◦ 16 TEST ◦ ◦
17 WR NC ◦ 18 SEL NC ◦
19 RXD ◦ NC 20 BUSY ◦ ◦
NC : No Connection
◦ : Connection
Table-10 CONNECTOR PIN CONNECTION
4-2. WRITE-IN TIMING (See Fig.2)
4-2-1. SERIAL INPUT
WR
START
D0
D1
D2
D3
D4
D5
D6
D7
STOP
BUSY
ƒ ‚
t(DATA) = 10 6 /baud rate [µs]
(This depends on the selection of the baud rate.)
‚ t(DATA) /2 [µs] (Busy becomes “H” at the center of stop bit.)
ƒ t(WAIT) : 0 [µs] Max.
Fig.2 WRITE-IN TIMING
AN-E-2211D [8/13]

4-2-2. PARALLEL INPUT
1
2
DATA
SEL
3
4
WR
5
BUSY
6
7
8
Fig.3 WRITE-IN TIMING
t su(DATA) 65ns −
‚ t h(DATA) 55ns −
ƒ t su(SEL ) 75ns −
„ t h(SEL ) 0ns −
… t pw( WR ) 75ns −
† t wait(1) 0ns −
‡ t wait(2) 200ns −
ˆ t delay − 50ns
Min. Max. Note
Table-12
For Min 200ns, WR should not be active (positive H),
after BUSY is “L”.
AN-E-2211D [9/13]

M204SD01AA MECHANICAL DRAWING
FIGURE-1
AN-E-2211D [10/13]

M204SD01AA CIRCUIT BLOCK DIAGRAM
FIGURE-2
D0∼D7
WR
SEL
RXD
TEST
BUSY
Vcc(+5V)
GND
X1
OSC
OSC
ACK
AIN
CPU
D0∼D7
WR
SEL
DATA
RXD
RESET
BLANK
ADDRESS
GCK
GIN
TEST
BUSY
DC/DC
CONVERTER
J1
J2
J3
ANODE DRIVER
(40bits)
ANODE DRIVER
(40bits)
RAM
20 digits, 4rows
5×7 dot
PROM
GRID 1-40
GRID DRIVER
(40bits)
PARALLEL - SERIAL SELECT
CLOCK BAUDRATE SELECT
ANODE DRIVER
GRID DRIVER
FILAMENT
ANODE 1-70
AN-E-2211D [11/13]

M204SD01AA DISPLAY CHARACTER CODE
FIGURE-3
D7
D6
D5
D4
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
D3 D2 D1 D0 0 1 2 3 4 5 6 7 8 9 A B C D E F
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
0 0 0 0
0
DP
SP
0 0 0 1
1
DC1
0 0 1 0
2
DC2
0 0 1 1
3
DEF
0 1 0 0
4
DIM
0 1 0 1
5
0 1 1 0
6
0 1 1 1
7
1 0 0 0
8
BS
1 0 0 1
9
HT
1 0 1 0
A
LF
1 0 1 1
B
1 1 0 0
C
1 1 0 1
D
CR
UF0
1 1 1 0
E
UF1
1 1 1 1
F
RST
UF2
SP:SPACE
AN-E-2211D [12/13]

5. WARRANTY
This display module is guaranteed for 1 year after shipment from FUTABA.
6. OPERATING RECOMMENDATION
6-1. Avoid applying excessive shock or vibration beyond the specification for this module.
6-2. Since VFDs are made of glass material, careful handling is important.
6-3. Applying lower voltage than the specified may cause non activation for selected pixels.
Conversely, higher voltage may cause non-selected pixel to be activated. If such a
phenomenon is observed, check the voltage level of the power supply.
6-4. Avoid plugging or unplugging the interface connection with the power on.
6-5. If the start up time of the supply voltage is slow, the controller may not be reset.
The supply voltage must be risen up to the specified voltage level within 30msec.
6-6. Avoid using the module where excessive noise interference is expected. Noise affects the
interface signal and causes improper operation.
Keep the length of the interface cable less than 50cm (When the longer cable is required,
please contact FUTABA engineering.).
6-7. When power supply is turned off, the capacitor does not discharge immediately.
The high voltage applied to the VFD must not contact the controller IC. (The shorting of the
mounted components within 30 seconds after power off may cause damage.)
AN-E-2211D [13/13]